San Francisco (initials SF ) (/ˌsæn frənˈsɪskoʊ/, Spanish for Saint Francis; Spanish: [san franˈsisko] ), officially the City and County of San Francisco, is the cultural, commercial, and financial center of Northern California. The consolidated city-county covers an area of about 47.9 square miles (124 km 2 ),  mostly at the north end of the San Francisco Peninsula in the San Francisco Bay Area. It is the fourth-most populous city in California, and the 13th-most populous in the United States, with a 2016 census-estimated population of 870,887.  The population is projected to reach 1 million by 2033.  As of 2016, San Francisco County was the 7th highest-income county in the United States, with a per capita personal income of over $110,418. 
San Francisco was founded on June 29, 1776, when colonists from Spain established Presidio of San Francisco at the Golden Gate and Mission San Francisco de Asís a few miles away, all named for St. Francis of Assisi.  The California Gold Rush of 1849 brought rapid growth, making it the largest city on the West Coast at the time. San Francisco became a consolidated city-county in 1856. After three-quarters of the city was destroyed by the 1906 earthquake and fire,  San Francisco was quickly rebuilt, hosting the Panama-Pacific International Exposition nine years later. In World War II, San Francisco was a major port of embarkation for service members shipping out to the Pacific Theater.  It then became the birthplace of the United Nations in 1945.    After the war, the confluence of returning servicemen, massive immigration, liberalizing attitudes, along with the rise of the " hippie " counterculture, the Sexual Revolution, the Peace Movement growing from opposition to United States involvement in the Vietnam War, and other factors led to the Summer of Love and the gay rights movement, cementing San Francisco as a center of liberal activism in the United States. Politically, the city votes strongly along liberal Democratic Party lines.
A popular tourist destination,  San Francisco is known for its cool summers, fog, steep rolling hills, eclectic mix of architecture, and landmarks, including the Golden Gate Bridge, cable cars, the former Alcatraz Federal Penitentiary, Fisherman's Wharf, and its Chinatown district. San Francisco is also the headquarters of five major banking institutions and various other companies such as Levi Strauss & Co., Gap Inc., Fitbit, Salesforce.com, Dropbox, Reddit, Square, Inc., Dolby, Airbnb, Weebly, Pacific Gas and Electric Company, Yelp, Pinterest, Twitter, Uber, Lyft, Mozilla, Wikimedia Foundation, Craigslist and Weather Underground. It is home to number of educational and cultural institutions, such as the University of California, San Francisco (UCSF), the De Young Museum, the San Francisco Museum of Modern Art, and the California Academy of Sciences.
San Francisco has several nicknames, including "The City by the Bay", "Golden Gate City",  "Frisco", "SF", "San Fran", "Fog City", and as well as older ones like "The City that Knows How", "Baghdad by the Bay", "The Paris of the West", or simply "The City".  As of 2017, San Francisco is ranked high on world liveability rankings. 
The earliest archaeological evidence of human habitation of the territory of the city of San Francisco dates to 3000 BC.  The Yelamu group of the Ohlone people resided in a few small villages when an overland Spanish exploration party, led by Don Gaspar de Portolà, arrived on November 2, 1769, the first documented European visit to San Francisco Bay.  Seven years later, on March 28, 1776, the Spanish established the Presidio of San Francisco, followed by a mission, Mission San Francisco de Asís (Mission Dolores), established by the Spanish explorer Juan Bautista de Anza. 
Upon independence from Spain in 1821, the area became part of Mexico. Under Mexican rule, the mission system gradually ended, and its lands became privatized. In 1835, Englishman William Richardson erected the first independent homestead,  near a boat anchorage around what is today Portsmouth Square. Together with Alcalde Francisco de Haro, he laid out a street plan for the expanded settlement, and the town, named Yerba Buena, began to attract American settlers. Commodore John D. Sloat claimed California for the United States on July 7, 1846, during the Mexican–American War, and Captain John B. Montgomery arrived to claim Yerba Buena two days later. Yerba Buena was renamed San Francisco on January 30 of the next year, and Mexico officially ceded the territory to the United States at the end of the war. Despite its attractive location as a port and naval base, San Francisco was still a small settlement with inhospitable geography. 
The California Gold Rush brought a flood of treasure seekers (known as "forty-niners", as in "1849"). With their sourdough bread in tow,  prospectors accumulated in San Francisco over rival Benicia,  raising the population from 1,000 in 1848 to 25,000 by December 1849.  The promise of fabulous riches was so strong that crews on arriving vessels deserted and rushed off to the gold fields, leaving behind a forest of masts in San Francisco harbor.  Some of these approximately 500 abandoned ships were used at times as storeships, saloons and hotels; many were left to rot and some were sunk to establish title to the underwater lot. By 1851 the harbor was extended out into the bay by wharves while buildings were erected on piles among the ships. By 1870 Yerba Buena Cove had been filled to create new land. Buried ships are occasionally exposed when foundations are dug for new buildings. 
California was quickly granted statehood in 1850 and the U.S. military built Fort Point at the Golden Gate and a fort on Alcatraz Island to secure the San Francisco Bay. Silver discoveries, including the Comstock Lode in Nevada in 1859, further drove rapid population growth.  With hordes of fortune seekers streaming through the city, lawlessness was common, and the Barbary Coast section of town gained notoriety as a haven for criminals, prostitution, and gambling. 
Entrepreneurs sought to capitalize on the wealth generated by the Gold Rush. Early winners were the banking industry, with the founding of Wells Fargo in 1852 and the Bank of California in 1864. Development of the Port of San Francisco and the establishment in 1869 of overland access to the eastern U.S. rail system via the newly completed Pacific Railroad (the construction of which the city only reluctantly helped support ) helped make the Bay Area a center for trade. Catering to the needs and tastes of the growing population, Levi Strauss opened a dry goods business and Domingo Ghirardelli began manufacturing chocolate. Immigrant laborers made the city a polyglot culture, with Chinese Railroad Workers, drawn to "Old Gold Mountain", creating the city's Chinatown quarter. In 1870, Asians made up 8% of the population.  The first cable cars carried San Franciscans up Clay Street in 1873. The city's sea of Victorian houses began to take shape, and civic leaders campaigned for a spacious public park, resulting in plans for Golden Gate Park. San Franciscans built schools, churches, theaters, and all the hallmarks of civic life. The Presidio developed into the most important American military installation on the Pacific coast.  By 1890, San Francisco's population approached 300,000, making it the eighth-largest city in the United States at the time. Around 1901, San Francisco was a major city known for its flamboyant style, stately hotels, ostentatious mansions on Nob Hill, and a thriving arts scene.  The first North American plague epidemic was the San Francisco plague of 1900–1904. 
At 5:12 am on April 18, 1906, a major earthquake struck San Francisco and northern California. As buildings collapsed from the shaking, ruptured gas lines ignited fires that spread across the city and burned out of control for several days. With water mains out of service, the Presidio Artillery Corps attempted to contain the inferno by dynamiting blocks of buildings to create firebreaks.  More than three-quarters of the city lay in ruins, including almost all of the downtown core.  Contemporary accounts reported that 498 people lost their lives, though modern estimates put the number in the several thousands.  More than half of the city's population of 400,000 was left homeless.  Refugees settled temporarily in makeshift tent villages in Golden Gate Park, the Presidio, on the beaches, and elsewhere. Many fled permanently to the East Bay.
Rebuilding was rapid and performed on a grand scale. Rejecting calls to completely remake the street grid, San Franciscans opted for speed. Amadeo Giannini's Bank of Italy, later to become Bank of America, provided loans for many of those whose livelihoods had been devastated. The influential San Francisco Planning and Urban Research Association or SPUR was founded in 1910 to address the quality of housing after the earthquake.  The earthquake hastened development of western neighborhoods that survived the fire, including Pacific Heights, where many of the city's wealthy rebuilt their homes.  In turn, the destroyed mansions of Nob Hill became grand hotels. City Hall rose again in splendid Beaux Arts style, and the city celebrated its rebirth at the Panama-Pacific International Exposition in 1915. 
It was during this period San Francisco built some of its most important infrastructure. Civil Engineer Michael O'Shaughnessy was hired by San Francisco Mayor James Rolph as chief engineer for the city in September 1912 to supervise the construction of the Twin Peaks Reservoir, the Stockton Street Tunnel, the Twin Peaks Tunnel, the San Francisco Municipal Railway, the Auxiliary Water Supply System, and new sewers. San Francisco's streetcar system, of which the J, K, L, M, and N lines survive today, was pushed to completion by O'Shaughnessy between 1915 and 1927. It was the O'Shaughnessy Dam, Hetch Hetchy Reservoir, and Hetch Hetchy Aqueduct that would have the largest effect on San Francisco.  An abundant water supply enabled San Francisco to develop into the city it has become today.
In ensuing years, the city solidified its standing as a financial capital; in the wake of the 1929 stock market crash, not a single San Francisco-based bank failed.  Indeed, it was at the height of the Great Depression that San Francisco undertook two great civil engineering projects, simultaneously constructing the San Francisco–Oakland Bay Bridge and the Golden Gate Bridge, completing them in 1936 and 1937, respectively. It was in this period that the island of Alcatraz, a former military stockade, began its service as a federal maximum security prison, housing notorious inmates such as Al Capone, and Robert Franklin Stroud, The Birdman of Alcatraz. San Francisco later celebrated its regained grandeur with a World's fair, the Golden Gate International Exposition in 1939–40, creating Treasure Island in the middle of the bay to house it.
During World War II, the Hunters Point Naval Shipyard became a hub of activity, and Fort Mason became the primary port of embarkation for service members shipping out to the Pacific Theater of Operations.  The explosion of jobs drew many people, especially African Americans from the South, to the area. After the end of the war, many military personnel returning from service abroad and civilians who had originally come to work decided to stay. The United Nations Charter creating the United Nations was drafted and signed in San Francisco in 1945 and, in 1951, the Treaty of San Francisco officially ended the war with Japan.
Urban planning projects in the 1950s and 1960s involved widespread destruction and redevelopment of west-side neighborhoods and the construction of new freeways, of which only a series of short segments were built before being halted by citizen-led opposition.  The onset of containerization made San Francisco's small piers obsolete, and cargo activity moved to the larger Port of Oakland.  The city began to lose industrial jobs and turned to tourism as the most important segment of its economy.  The suburbs experienced rapid growth, and San Francisco underwent significant demographic change, as large segments of the white population left the city, supplanted by an increasing wave of immigration from Asia and Latin America.   From 1950 to 1980, the city lost over 10 percent of its population.
Over this period, San Francisco became a magnet for America's counterculture. Beat Generation writers fueled the San Francisco Renaissance and centered on the North Beach neighborhood in the 1950s.  Hippies flocked to Haight-Ashbury in the 1960s, reaching a peak with the 1967 Summer of Love.  In 1974, the Zebra murders left at least 16 people dead.  In the 1970s, the city became a center of the gay rights movement, with the emergence of The Castro as an urban gay village, the election of Harvey Milk to the Board of Supervisors, and his assassination, along with that of Mayor George Moscone, in 1978. 
Bank of America completed 555 California Street in 1969 and the Transamerica Pyramid was completed in 1972,  igniting a wave of " Manhattanization " that lasted until the late 1980s, a period of extensive high-rise development downtown. The 1980s also saw a dramatic increase in the number of homeless people in the city, an issue that remains today, despite many attempts to address it.  The 1989 Loma Prieta earthquake caused destruction and loss of life throughout the Bay Area. In San Francisco, the quake severely damaged structures in the Marina and South of Market districts and precipitated the demolition of the damaged Embarcadero Freeway and much of the damaged Central Freeway, allowing the city to reclaim The Embarcadero as its historic downtown waterfront and revitalizing the Hayes Valley neighborhood.
Two recent decades have seen two booms driven by the internet industry. First was the dot-com boom of the late 1990s, startup companies invigorated the San Francisco economy. Large numbers of entrepreneurs and computer application developers moved into the city, followed by marketing, design, and sales professionals, changing the social landscape as once-poorer neighborhoods became increasingly gentrified.  Demand for new housing and office space ignited a second wave of high-rise development, this time in the South of Market district.  By 2000, the city's population reached new highs, surpassing the previous record set in 1950. When the bubble burst in 2001, many of these companies folded and their employees were laid off. Yet high technology and entrepreneurship remain mainstays of the San Francisco economy. By the mid-2000s (decade), the social media boom had begun, with San Francisco becoming a popular location for tech offices and a popular place to live for people employed in Silicon Valley companies such as Apple and Google. 
The Ferry Station Post Office Building, Armour & Co. Building, Atherton House, and YMCA Hotel are historic buildings among dozens of historical landmarks in the city according to the National Register of Historic Places listings in San Francisco.
San Francisco is located on the West Coast of the United States at the north end of the San Francisco Peninsula and includes significant stretches of the Pacific Ocean and San Francisco Bay within its boundaries. Several picturesque islands — Alcatraz, Treasure Island and the adjacent Yerba Buena Island, and small portions of Alameda Island, Red Rock Island, and Angel Island —are part of the city. Also included are the uninhabited Farallon Islands, 27 miles (43 km) offshore in the Pacific Ocean. The mainland within the city limits roughly forms a "seven-by-seven-mile square", a common local colloquialism referring to the city's shape, though its total area, including water, is nearly 232 square miles (600 km 2 ).
There are more than 50 hills within city limits.  Some neighborhoods are named after the hill on which they are situated, including Nob Hill, Potrero Hill, and Russian Hill. Near the geographic center of the city, southwest of the downtown area, are a series of less densely populated hills. Twin Peaks, a pair of hills forming one of the city's highest points, forms a popular overlook spot. San Francisco's tallest hill, Mount Davidson, is 928 feet (283 m) high and is capped with a 103-foot (31 m) tall cross built in 1934.  Dominating this area is Sutro Tower, a large red and white radio and television transmission tower.
The nearby San Andreas and Hayward Faults are responsible for much earthquake activity, although neither physically passes through the city itself. The San Andreas Fault caused the earthquakes in 1906 and 1989. Minor earthquakes occur on a regular basis. The threat of major earthquakes plays a large role in the city's infrastructure development. The city constructed an auxiliary water supply system and has repeatedly upgraded its building codes, requiring retrofits for older buildings and higher engineering standards for new construction.  However, there are still thousands of smaller buildings that remain vulnerable to quake damage.  USGS has released the California earthquake forecast which models earthquake occurrence in California. 
San Francisco's shoreline has grown beyond its natural limits. Entire neighborhoods such as the Marina, Mission Bay, and Hunters Point, as well as large sections of the Embarcadero, sit on areas of landfill. Treasure Island was constructed from material dredged from the bay as well as material resulting from tunneling through Yerba Buena Island during the construction of the Bay Bridge. Such land tends to be unstable during earthquakes. The resulting soil liquefaction causes extensive damage to property built upon it, as was evidenced in the Marina district during the 1989 Loma Prieta earthquake.  Most of the city's natural watercourses, such as Islais Creek and Mission Creek, have been culverted and built over, although the Public Utilities Commission is studying proposals to daylight or restore some creeks. 
The historic center of San Francisco is the northeast quadrant of the city anchored by Market Street and the waterfront. It is here that the Financial District is centered, with Union Square, the principal shopping and hotel district, and the Tenderloin nearby. Cable cars carry riders up steep inclines to the summit of Nob Hill, once the home of the city's business tycoons, and down to the waterfront tourist attractions of Fisherman's Wharf, and Pier 39, where many restaurants feature Dungeness crab from a still-active fishing industry. Also in this quadrant are Russian Hill, a residential neighborhood with the famously crooked Lombard Street; North Beach, the city's Little Italy and the former center of the Beat Generation; and Telegraph Hill, which features Coit Tower. Abutting Russian Hill and North Beach is San Francisco's Chinatown, the oldest Chinatown in North America.    The South of Market, which was once San Francisco's industrial core, has seen significant redevelopment following the construction of AT&T Park and an infusion of startup companies. New skyscrapers, live-work lofts, and condominiums dot the area. Further development is taking place just to the south in Mission Bay area, a former railroad yard, which now has a second campus of the University of California, San Francisco, and where the new Warriors arena will be built. 
West of downtown, across Van Ness Avenue, lies the large Western Addition neighborhood, which became established with a large African American population after World War II. The Western Addition is usually divided into smaller neighborhoods including Hayes Valley, the Fillmore, and Japantown, which was once the largest Japantown in North America but suffered when its Japanese American residents were forcibly removed and interned during World War II. The Western Addition survived the 1906 earthquake with its Victorians largely intact, including the famous " Painted Ladies ", standing alongside Alamo Square. To the south, near the geographic center of the city is Haight-Ashbury, famously associated with 1960s hippie culture. The Haight is now home to some expensive boutiques  and a few controversial chain stores,  although it still retains some bohemian character.
North of the Western Addition is Pacific Heights, an affluent neighborhood that features the homes built by wealthy San Franciscans in the wake of the 1906 earthquake. Directly north of Pacific Heights facing the waterfront is the Marina, a neighborhood popular with young professionals that was largely built on reclaimed land from the Bay. 
In the south-east quadrant of the city is the Mission District —populated in the 19th century by Californios and working-class immigrants from Germany, Ireland, Italy, and Scandinavia. In the 1910s, a wave of Central American immigrants settled in the Mission and, in the 1950s, immigrants from Mexico began to predominate.  In recent years, gentrification has changed the demographics of parts of the Mission from Latino, to twenty-something professionals. Noe Valley to the southwest and Bernal Heights to the south are both increasingly popular among young families with children. East of the Mission is the Potrero Hill neighborhood, a mostly residential neighborhood that features sweeping views of downtown San Francisco. West of the Mission, the area historically known as Eureka Valley, now popularly called the Castro, was once a working-class Scandinavian and Irish area. It has become North America's first and best known gay village, and is now the center of gay life in the city.  Located near the city's southern border, the Excelsior District is one of the most ethnically diverse neighborhoods in San Francisco. The predominantly African American Bayview-Hunters Point in the far southeast corner of the city is one of the poorest neighborhoods and suffers from a high rate of crime, though the area has been the focus of several revitalizing and controversial urban renewal projects.
The construction of the Twin Peaks Tunnel in 1918 connected southwest neighborhoods to downtown via streetcar, hastening the development of West Portal, and nearby affluent Forest Hill and St. Francis Wood. Further west, stretching all the way to the Pacific Ocean and north to Golden Gate Park lies the vast Sunset District, a large middle class area with a predominantly Asian population.  The northwestern quadrant of the city contains the Richmond, also a mostly middle-class neighborhood north of Golden Gate Park, home to immigrants from other parts of Asia as well as many Russian and Ukrainian immigrants. Together, these areas are known as The Avenues. These two districts are each sometimes further divided into two regions: the Outer Richmond and Outer Sunset can refer to the more western portions of their respective district and the Inner Richmond and Inner Sunset can refer to the more eastern portions.
Many piers remained derelict for years until the demolition of the Embarcadero Freeway reopened the downtown waterfront, allowing for redevelopment. The centerpiece of the port, the Ferry Building, while still receiving commuter ferry traffic, has been restored and redeveloped as a gourmet marketplace.
San Francisco has a warm-summer Mediterranean climate (Köppen Csb) characteristic of California's coast, with moist mild winters and dry summers.  San Francisco's weather is strongly influenced by the cool currents of the Pacific Ocean on the west side of the city, and the water of San Francisco Bay to the north and east. This moderates temperature swings and produces a remarkably mild year-round climate with little seasonal temperature variation.
Among major U.S. cities, San Francisco has the coolest daily mean, maximum, and minimum temperatures for June, July, and August.  During the summer, rising hot air in California's interior valleys creates a low pressure area that draws winds from the North Pacific High through the Golden Gate, which creates the city's characteristic cool winds and fog.  The fog is less pronounced in eastern neighborhoods and during the late summer and early fall. As a result, the year's warmest month, on average, is September, and on average, October is warmer than July, especially in daytime.
Because of its sharp topography and maritime influences, San Francisco exhibits a multitude of distinct microclimates. The high hills in the geographic center of the city are responsible for a 20% variance in annual rainfall between different parts of the city. They also protect neighborhoods directly to their east from the foggy and sometimes very cold and windy conditions experienced in the Sunset District; for those who live on the eastern side of the city, San Francisco is sunnier, with an average of 260 clear days, and only 105 cloudy days per year.
Temperatures reach or exceed 80 °F (27 °C) on an average of only 21 and 23 days a year at downtown and San Francisco International Airport (SFO), respectively.  The dry period of May to October is mild to warm, with the normal monthly mean temperature peaking in September at 62.7 °F (17.1 °C).  The rainy period of November to April is slightly cooler, with the normal monthly mean temperature reaching its lowest in January at 51.3 °F (10.7 °C).  On average, there are 73 rainy days a year, and annual precipitation averages 23.65 inches (601 mm).  Variation in precipitation from year to year is high. Above average rain years are often associated with warm El Niño conditions in the Pacific while dry years often occur in cold water La Niña periods. In 2013 (a "La Niña" year), a record low 5.59 in (142 mm) of rainfall was recorded at downtown San Francisco, where records have been kept since 1849.  Snowfall in the city is very rare, with only 10 measurable accumulations recorded since 1852, most recently in 1976 when up to 5 inches (130 mm) fell on Twin Peaks.  
The highest recorded temperature at the official National Weather Service downtown observation station (currently at the United States Mint building) was 106 °F (41 °C) on September 1, 2017.  The lowest recorded temperature was 27 °F (−3 °C) on December 11, 1932.  The National Weather Service provides a helpful visual aid  graphing the information in the table below to display visually by month the annual typical temperatures, the past year's temperatures, and record temperatures.
|Climate data for San Francisco (downtown),  1981–2010 normals, extremes 1849–present|
|Record high °F (°C)||79 (26)||81 (27)||87 (31)||94 (34)||97 (36)||103 (39)||98 (37)||98 (37)||106 (41)||102 (39)||86 (30)||76 (24)||106 (41)|
|Mean maximum °F (°C)||67.3 (19.6)||72.5 (22.5)||75.7 (24.3)||82.3 (27.9)||82.7 (28.2)||86.0 (30)||83.1 (28.4)||85.5 (29.7)||89.6 (32)||88.1 (31.2)||76.1 (24.5)||66.4 (19.1)||94.3 (34.6)|
|Average high °F (°C)||56.9 (13.8)||60.2 (15.7)||61.8 (16.6)||63.1 (17.3)||64.3 (17.9)||66.4 (19.1)||66.5 (19.2)||68.1 (20.1)||70.2 (21.2)||69.2 (20.7)||63.1 (17.3)||57.1 (13.9)||63.9 (17.7)|
|Daily mean °F (°C)||51.3 (10.7)||53.9 (12.2)||55.1 (12.8)||56.2 (13.4)||57.6 (14.2)||59.6 (15.3)||60.3 (15.7)||61.6 (16.4)||62.7 (17.1)||61.5 (16.4)||56.6 (13.7)||51.6 (10.9)||57.3 (14.1)|
|Average low °F (°C)||45.7 (7.6)||47.5 (8.6)||48.5 (9.2)||49.2 (9.6)||51.0 (10.6)||52.8 (11.6)||54.1 (12.3)||55.1 (12.8)||55.1 (12.8)||53.7 (12.1)||50.1 (10.1)||46.1 (7.8)||50.7 (10.4)|
|Mean minimum °F (°C)||40.3 (4.6)||41.8 (5.4)||43.6 (6.4)||45.1 (7.3)||47.7 (8.7)||50.2 (10.1)||51.5 (10.8)||52.6 (11.4)||52.0 (11.1)||49.6 (9.8)||44.2 (6.8)||40.1 (4.5)||38.2 (3.4)|
|Record low °F (°C)||29 (−2)||31 (−1)||33 (1)||40 (4)||42 (6)||46 (8)||47 (8)||46 (8)||47 (8)||43 (6)||38 (3)||27 (−3)||27 (−3)|
|Average rainfall inches (mm)||4.50 (114.3)||4.46 (113.3)||3.26 (82.8)||1.46 (37.1)||0.70 (17.8)||0.16 (4.1)||0.00 (0)||0.06 (1.5)||0.21 (5.3)||1.12 (28.4)||3.16 (80.3)||4.56 (115.8)||23.65 (600.7)|
|Average rainy days (≥ 0.01 in)||11.7||11.1||11.0||6.5||3.8||1.5||0.3||1.0||1.7||3.9||8.9||11.6||73.0|
|Average relative humidity (%)||80||77||75||72||72||71||75||75||73||71||75||78||74.5|
|Mean monthly sunshine hours||185.9||207.7||269.1||309.3||325.1||311.4||313.3||287.4||271.4||247.1||173.4||160.6||3,061.7|
|Percent possible sunshine||61||69||73||78||74||70||70||68||73||71||57||54||69|
|Source #1: NOAA (sun 1961–1974) |
|Source #2: Met Office for humidity |
| Sources:     Source: |
The U.S. Census Bureau estimates San Francisco's population to be 870,887 as of July 1, 2016, with a population density of 18,573/sq mi.  San Francisco is the second-most densely populated major American city behind only New York (among cities greater than 200,000 population), and the fifth-most densely populated U.S. county. 
San Francisco is the traditional focal point of the San Francisco Bay Area and forms part of the five-county San Francisco–Oakland–Hayward, CA Metropolitan Statistical Area, a region of 4.6 million people. It is also part of the greater 12-county San Jose-San Francisco-Oakland, CA Combined Statistical Area, whose population is over 8.7 million, making it the fifth-largest in the United States as of July 1, 2015. 
Race, ethnicity, religion and languages
San Francisco has a minority-majority population, as non-Hispanic whites comprise less than half of the population, 41.9%, down from 92.5% in 1940.  As of the 2010 census, the ethnic makeup and population of San Francisco included: 390,387 whites (48%), 267,915 Asians (33%), 48,870 African Americans (6%), and others. There were 121,744 Hispanics or Latinos of any race (15%).
In 2010, residents of Chinese ethnicity constituted the largest single ethnic minority group in San Francisco at 21% of the population; the other Asian groups are Filipinos (5%) and Vietnamese (2%).  The population of Chinese ancestry is most heavily concentrated in Chinatown, Sunset District, and Richmond District, whereas Filipinos are most concentrated in the Crocker-Amazon (which is contiguous with the Filipino community of Daly City, which has one of the highest concentrations of Filipinos in North America), as well as in SoMa.  The Tenderloin District is home to a large portion of the city's Vietnamese population as well as businesses and restaurants, which is known as the city's Little Saigon. 
The principal Hispanic groups in the city were those of Mexican (7%) and Salvadoran (2%) ancestry. The Hispanic population is most heavily concentrated in the Mission District, Tenderloin District, and Excelsior District. The city's percentage of Hispanic residents is less than half of that of the state. The population of African Americans in San Francisco has declined to 6% of the city's population.   The percentage of African Americans in San Francisco is similar to that of California.  The majority of the city's black population reside within the neighborhoods of Bayview-Hunters Point, Visitacion Valley, and in the Fillmore District.
According to a 2014 study by the Pew Research Center, the largest religious groupings in San Francisco's metropolitan area are Christians (48%), followed by those of no religion (35%), Hindus (5%), Jews (3%), Buddhists (2%), Muslims (1%) and a variety of other religions have smaller followings. According to the same study by the Pew Research Center, about 20% of residents in the area are Protestant, and 25% professing Roman Catholic beliefs. Meanwhile, 10% of the residents in metropolitan San Francisco identifies as agnostics, while 5% identifies as atheists.
As of 2010, 55% (411,728) of San Francisco residents spoke English at home as a primary language, while 19% (140,302) spoke a variety of Chinese (mostly Taishanese and Cantonese   ), 12% (88,147) Spanish, 3% (25,767) Tagalog, and 2% (14,017) Russian. In total, 45% (342,693) of San Francisco's population spoke a mother language other than English. 
Education, households, and income
Of all major cities in the United States, San Francisco has the second-highest percentage of residents with a college degree, behind only Seattle. Over 44% of adults have a bachelor's or higher degree.  San Francisco had the highest rate at 7,031 per square mile, or over 344,000 total graduates in the city's 46.7 square miles (121 km 2 ). 
San Francisco has the highest percentage of gay and lesbian individuals of any of the 50 largest U.S. cities, at 15%.  San Francisco also has the highest percentage of same-sex households of any American county, with the Bay Area having a higher concentration than any other metropolitan area. 
|Income in 2011|
|Per capita income||$46,777|
|Median household income||$72,947|
|Median family income||$87,329|
San Francisco ranks third of American cities in median household income  with a 2007 value of $65,519.  Median family income is $81,136.  An emigration of middle-class families has left the city with a lower proportion of children, 15%, than any other large American city.  The city's poverty rate is 12%, lower than the national average.  Homelessness has been a chronic problem for San Francisco since the early 1970s.  The city is believed to have the highest number of homeless inhabitants per capita of any major U.S. city.  
There are 345,811 households in the city, out of which: 133,366 households (39%) were individuals, 109,437 (32%) were opposite-sex married couples, 63,577 (18%) had children under the age of 18 living in them, 21,677 (6%) were unmarried opposite-sex partnerships, and 10,384 (3%) were same-sex married couples or partnerships. The average household size was 2.26; the average family size was 3.11. 452,986 people (56%) lived in rental housing units, and 327,985 people (41%) lived in owner-occupied housing units. The median age of the city population is 38 years.
Homelessness, historically, has been a major problem in the city and remains a growing problem in modern times.  The homeless population is estimated to be 13,500 with 6,500 living on the streets. 
San Francisco has a diversified service economy, with employment spread across a wide range of professional services, including financial services, tourism, and (increasingly) high technology.  In 2016, approximately 27% of workers were employed in professional business services; 14% in leisure and hospitality; 13% in government services; 12% in education and health care; 11% in trade, transportation, and utilities; and 8% in financial activities.  In 2016, GDP in the five-county San Francisco metropolitan area grew 5.4% to $470.5 billion.  Additionally, in 2016 the 12-county San Jose-San Francisco-Oakland combined statistical area had a GDP of $820.9 billion,  ranking 3rd among CSA s, and ahead of all but 17 countries. As of 2016, San Francisco County was the 7th highest-income county in the United States (among over 3,000), with a per capita personal income of $110,418.  Marin County, directly to the north over the Golden Gate Bridge, and San Mateo County, directly to the south on the Peninsula, were 5th and 11th highest-income counties respectively.
The legacy of the California Gold Rush turned San Francisco into the principal banking and finance center of the West Coast in the early twentieth century.  Montgomery Street in the Financial District became known as the " Wall Street of the West ", home to the Federal Reserve Bank of San Francisco, the Wells Fargo corporate headquarters, and the site of the now-defunct Pacific Coast Stock Exchange.  Bank of America, a pioneer in making banking services accessible to the middle class, was founded in San Francisco and in the 1960s, built the landmark modern skyscraper at 555 California Street for its corporate headquarters. Many large financial institutions, multinational banks, and venture capital firms are based in or have regional headquarters in the city. With over 30 international financial institutions,  six Fortune 500 companies,  and a large support infrastructure of professional services—including law, public relations, architecture and design—San Francisco is designated as an Alpha(-) World City.  The 2017 Global Financial Centres Index ranked San Francisco as the sixth most competitive financial center in the world. 
Since the 1990s, San Francisco's economy has diversified away from finance and tourism towards the growing fields of high tech, biotechnology, and medical research.  Technology jobs accounted for just 1 percent of San Francisco's economy in 1990, growing to 4 percent in 2010 and an estimated 8 percent by the end of 2013.  San Francisco became an epicenter of Internet start-up companies during the dot-com bubble of the 1990s and the subsequent social media boom of the late 2000s (decade).  Since 2010, San Francisco proper has attracted an increasing share of venture capital investments as compared to nearby Silicon Valley, attracting 423 financings worth US$4.58 billion in 2013.   In 2004, the city approved a payroll tax exemption for biotechnology companies  to foster growth in the Mission Bay neighborhood, site of a second campus and hospital of the University of California, San Francisco (UCSF). Mission Bay hosts the UCSF Medical Center, the California Institute for Regenerative Medicine, California Institute for Quantitative Biosciences, and Gladstone Institutes,  as well as more than 40 private-sector life sciences companies. 
The top employer in the city is the city government itself, employing 5.3% (25,000+ people) of the city's population, followed by UCSF with over 22,000 employees. Third—at 1.8% (8,500+ people)—is California Pacific Medical Center, the largest private-sector employer.  Small businesses with fewer than 10 employees and self-employed firms make up 85% of city establishments,  and the number of San Franciscans employed by firms of more than 1,000 employees has fallen by half since 1977.  The growth of national big box and formula retail chains into the city has been made intentionally difficult by political and civic consensus. In an effort to buoy small privately owned businesses in San Francisco and preserve the unique retail personality of the city, the Small Business Commission started a publicity campaign in 2004 to keep a larger share of retail dollars in the local economy,  and the Board of Supervisors has used the planning code to limit the neighborhoods where formula retail establishments can set up shop,  an effort affirmed by San Francisco voters.  However, by 2016, San Francisco was rated low by small businesses in a Business Friendliness Survey. 
Like many U.S. cities, San Francisco once had a significant manufacturing sector employing nearly 60,000 workers in 1969, but nearly all production left for cheaper locations by the 1980s.  As of 2014, San Francisco has seen a small resurgence in manufacturing, with more than 4,000 manufacturing jobs across 500 companies, doubling since 2011. The city's largest manufacturing employer is Anchor Brewing Company, and the largest by revenue is Timbuk2. 
Tourism and conventions
Tourism is one of the city's largest private-sector industries, accounting for more than one out of seven jobs in the city.   The city's frequent portrayal in music, film, and popular culture has made the city and its landmarks recognizable worldwide. It attracts the fifth-highest number of foreign tourists of any city in the United States  and is one of the 100 most visited cities worldwide.  More than 25 million visitors arrived in San Francisco in 2016, adding US$9.96 billion to the economy.  With a large hotel infrastructure and a world-class convention facility in the Moscone Center, San Francisco is a popular destination for annual conventions and conferences. 
Some of the most popular tourist attractions in San Francisco noted by the Travel Channel include the Golden Gate Bridge and Alamo Square Park, which is home to the famous " Painted Ladies ". Both of these locations were often used as landscape shots for the hit American sitcom Full House. There is also Lombard Street, known for its "crookedness" and beautiful views. Tourists also flood to Pier 39, which offers dining, shopping, entertainment, and beautiful views of the bay, sun-bathing seals, and the famous Alcatraz Island. 
San Francisco also offers tourists cultural and unique nightlife in its neighborhoods. 
The new Terminal Project at Pier 27 opened September 25, 2014 as a replacement for the old Pier 35.  Itineraries from San Francisco usually include round trip cruises to Alaska and Mexico.
A heightened interest in conventioneering in San Francisco, marked by the establishment of convention centers such as Yerba Buena, acted as a feeder into the local tourist economy and resulted in an increase in the hotel industry: "In 1959, the city had fewer than thirty-three hundred first-class hotel rooms; by 1970, the number was nine thousand; and by 1999, there were more than thirty thousand." The commodification of the Castro District has contributed to San Francisco's tourist economy. 
Culture and contemporary life
Although the Financial District, Union Square, and Fisherman's Wharf are well-known around the world, San Francisco is also characterized by its numerous culturally rich streetscapes featuring mixed-use neighborhoods anchored around central commercial corridors to which residents and visitors alike can walk. Because of these characteristics, San Francisco is ranked the second "most walkable" city in the United States by Walkscore.com.  Many neighborhoods feature a mix of businesses, restaurants and venues that cater to both the daily needs of local residents while also serving many visitors and tourists. Some neighborhoods are dotted with boutiques, cafés and nightlife such as Union Street in Cow Hollow, 24th Street in Noe Valley, Valencia Street in the Mission, Grant Avenue in North Beach, and Irving Street in the Inner Sunset. This approach especially has influenced the continuing South of Market neighborhood redevelopment with businesses and neighborhood services rising alongside high-rise residences. 
Since the 1990s, the demand for skilled information technology workers from local startups and nearby Silicon Valley has attracted white-collar workers from all over the world and created a high standard of living in San Francisco.  Many neighborhoods that were once blue-collar, middle, and lower class have been gentrifying, as many of the city's traditional business and industrial districts have experienced a renaissance driven by the redevelopment of the Embarcadero, including the neighborhoods South Beach and Mission Bay. The city's property values and household income have risen to among the highest in the nation,    creating a large and upscale restaurant, retail, and entertainment scene. According to a 2014 quality of life survey of global cities, San Francisco has the highest quality of living of any U.S. city.  However, due to the exceptionally high cost of living, many of the city's middle and lower-class families have been leaving the city for the outer suburbs of the Bay Area, or for California's Central Valley.  By June 2, 2015, the median rent was reported to be as high as $4,225.  The high cost of living is due in part to restrictive planning laws which limit new residential construction.
The international character that San Francisco has enjoyed since its founding is continued today by large numbers of immigrants from Asia and Latin America. With 39% of its residents born overseas,  San Francisco has numerous neighborhoods filled with businesses and civic institutions catering to new arrivals. In particular, the arrival of many ethnic Chinese, which accelerated beginning in the 1970s, has complemented the long-established community historically based in Chinatown throughout the city and has transformed the annual Chinese New Year Parade into the largest event of its kind outside China. 
With the arrival of the "beat" writers and artists of the 1950s and societal changes culminating in the Summer of Love in the Haight-Ashbury district during the 1960s, San Francisco became a center of liberal activism and of the counterculture that arose at that time. The Democrats and to a lesser extent the Green Party have dominated city politics since the late 1970s, after the last serious Republican challenger for city office lost the 1975 mayoral election by a narrow margin. San Francisco has not voted more than 20% for a Republican presidential or senatorial candidate since 1988.  In 2007, the city expanded its Medicaid and other indigent medical programs into the " Healthy San Francisco " program,  which subsidizes certain medical services for eligible residents.   
San Francisco also has had a very active environmental community. Starting with the founding of the Sierra Club in 1892 to the establishment of the non-profit Friends of the Urban Forest in 1981, San Francisco has been at the forefront of many global discussions regarding our natural environment.   The 1980 San Francisco Recycling Program was one of the earliest curbside recycling programs.  The city's GoSolarSF incentive promotes solar installations and the San Francisco Public Utilities Commission is rolling out the CleanPowerSF program to sell electricity from local renewable sources.   SF Greasecycle is a program to recycle used cooking oil for conversion to biodiesel. 
The Sunset Reservoir Solar Project, completed in 2010, installed 24,000 solar panels on the roof of the reservoir. The 5-megawatt plant more than tripled the city's 2-megawatt solar generation capacity when it opened in December 2010.  
San Francisco has long had an LGBT -friendly history. It was home to the first lesbian-rights organization in the United States, Daughters of Bilitis; the first openly gay person to run for public office in the United States, José Sarria; the first openly gay man to be elected to public office in California, Harvey Milk; the first openly lesbian judge appointed in the U.S., Mary C. Morgan; and the first transgender police commissioner, Theresa Sparks. The city's large gay population has created and sustained a politically and culturally active community over many decades, developing a powerful presence in San Francisco's civic life. Survey data released in 2015 by Gallup place the proportion of the San Francisco metro area at 6.2%, which is the highest such proportion observed of the 50 most populous metropolitan areas as measured by the polling organization. 
One of the most popular destinations for gay tourists internationally, the city hosts San Francisco Pride, one of the largest and oldest pride parades. San Francisco Pride events have been held continuously since 1972. The events are themed and a new theme is created each year. In 2013, over 1.5 million people attended, around 500,000 more than the previous year. 
Entertainment and performing arts
San Francisco's War Memorial and Performing Arts Center hosts some of the most enduring performing-arts companies in the country. The War Memorial Opera House houses the San Francisco Opera, the second-largest opera company in North America  as well as the San Francisco Ballet, while the San Francisco Symphony plays in Davies Symphony Hall.
The Fillmore is a music venue located in the Western Addition. It is the second incarnation of the historic venue that gained fame in the 1960s, housing the stage where now-famous musicians such as the Grateful Dead, Janis Joplin, Led Zeppelin and Jefferson Airplane first performed, fostering the San Francisco Sound.
San Francisco has a large number of theaters and live performance venues. Local theater companies have been noted for risk taking and innovation.  The Tony Award -winning non-profit American Conservatory Theater (A.C.T.) is a member of the national League of Resident Theatres. Other local winners of the Regional Theatre Tony Award include the San Francisco Mime Troupe.  San Francisco theaters frequently host pre- Broadway engagements and tryout runs,  and some original San Francisco productions have later moved to Broadway. 
The San Francisco Museum of Modern Art (SFMOMA) houses 20th century and contemporary works of art. It moved to its current building in the South of Market neighborhood in 1995 and attracted more than 600,000 visitors annually.  SFMOMA closed for renovation and expansion in 2013. The museum reopened on May 14, 2016 with an addition, designed by Snøhetta, that has doubled the museum's size. 
The Palace of the Legion of Honor holds primarily European antiquities and works of art at its Lincoln Park building modeled after its Parisian namesake. The de Young Museum in Golden Gate Park features American decorative pieces and anthropological holdings from Africa, Oceania and the Americas, while Asian art is housed in the Asian Art Museum. Opposite the de Young stands the California Academy of Sciences, a natural history museum that also hosts the Morrison Planetarium and Steinhart Aquarium. Located on Pier 15 on the Embarcadero, the Exploratorium is an interactive science museum. The Contemporary Jewish Museum is a non-collecting institution that hosts a broad array of temporary exhibitions. On Nob Hill, the Cable Car Museum is a working museum featuring the cable car power house, which drives the cables. 
Major League Baseball's San Francisco Giants have played in San Francisco since moving from New York in 1958. The Giants play at AT&T Park, which opened in 2000.  The Giants won World Series titles in 2010, 2012, and in 2014. The Giants have boasted such stars as Willie Mays, Willie McCovey and Barry Bonds. In 2012, San Francisco was ranked #1 in a study that examined which U.S. metro areas have produced the most Major Leaguers since 1920. 
The San Francisco 49ers of the National Football League (NFL) were the longest-tenured major professional sports franchise in the city until moving in 2013. The team began play in 1946 as an All-America Football Conference (AAFC) league charter member, moved to the NFL in 1950 and into Candlestick Park in 1971. The team began playing its home games at Levi's Stadium in Santa Clara in 2014, closer to the city of San Jose.   The 49ers won five Super Bowl titles in the 1980s and 1990s.
The San Francisco Warriors played in the NBA from 1962–1971, before being renamed the Golden State Warriors prior to the 1971–1972 season in an attempt to present the team as a representation of the whole state of California.  The Warrior's stadium, Oracle Arena, is currently located in Oakland, California.  They have won 5 championships,  including their most recent in 2017.
At the collegiate level, the San Francisco Dons compete in NCAA Division I. Bill Russell led the Don's basketball team to NCAA championships in 1955 and 1956. There is also the San Francisco State Gators, who compete in NCAA Division II.  AT&T Park hosted the annual Fight Hunger Bowl college football game from 2002 through 2013 before it moved to Santa Clara.
The Bay to Breakers footrace, held annually since 1912, is best known for colorful costumes and a celebratory community spirit.  The San Francisco Marathon attracts more than 21,000 participants.  The Escape from Alcatraz triathlon has, since 1980, attracted 2,000 top professional and amateur triathletes for its annual race.  The Olympic Club, founded in 1860, is the oldest athletic club in the United States. Its private golf course has hosted the U.S. Open on five occasions. San Francisco hosted the 2013 America's Cup yacht racing competition. 
With an ideal climate for outdoor activities, San Francisco has ample resources and opportunities for amateur and participatory sports and recreation. There are more than 200 miles (320 km) of bicycle paths, lanes and bike routes in the city.  San Francisco residents have often ranked among the fittest in the country.  Golden Gate Park has miles of paved and unpaved running trails as well as a golf course and disc golf course. Boating, sailing, windsurfing and kitesurfing are among the popular activities on San Francisco Bay, and the city maintains a yacht harbor in the Marina District.
Beaches and parks
Several of San Francisco's parks and nearly all of its beaches form part of the regional Golden Gate National Recreation Area, one of the most visited units of the National Park system in the United States with over 13 million visitors a year. Among the GGNRA's attractions within the city are Ocean Beach, which runs along the Pacific Ocean shoreline and is frequented by a vibrant surfing community, and Baker Beach, which is located in a cove west of the Golden Gate and part of the Presidio, a former military base. Also within the Presidio is Crissy Field, a former airfield that was restored to its natural salt marsh ecosystem. The GGNRA also administers Fort Funston, Lands End, Fort Mason, and Alcatraz. The National Park Service separately administers the San Francisco Maritime National Historical Park – a fleet of historic ships and waterfront property around Aquatic Park.
There are more than 220 parks maintained by the San Francisco Recreation & Parks Department.  The largest and best-known city park is Golden Gate Park,  which stretches from the center of the city west to the Pacific Ocean. Once covered in native grasses and sand dunes, the park was conceived in the 1860s and was created by the extensive planting of thousands of non-native trees and plants. The large park is rich with cultural and natural attractions such as the Conservatory of Flowers, Japanese Tea Garden and San Francisco Botanical Garden. Lake Merced is a fresh-water lake surrounded by parkland and near the San Francisco Zoo, a city-owned park that houses more than 250 animal species, many of which are endangered.  The only park managed by the California State Park system located principally in San Francisco, Candlestick Point was the state's first urban recreation area. 
Law and government
San Francisco—officially known as the City and County of San Francisco—is a consolidated city-county, a status it has held since the 1856 secession of what is now San Mateo County. It is the only such consolidation in California.  The mayor is also the county executive, and the county Board of Supervisors acts as the city council. The government of San Francisco is a charter city and is constituted of two co-equal branches. The executive branch is headed by the mayor and includes other citywide elected and appointed officials as well as the civil service. The 11-member Board of Supervisors, the legislative branch, is headed by a president and is responsible for passing laws and budgets, though San Franciscans also make use of direct ballot initiatives to pass legislation. 
The members of the Board of Supervisors are elected as representatives of specific districts within the city.  Upon the death or resignation of mayor, the President of the Board of Supervisors becomes acting mayor until the full Board elects an interim replacement for the remainder of the term. In 1978, Dianne Feinstein assumed the office following the assassination of George Moscone and was later selected by the board to finish the term. In 2011, Edwin M. Lee was selected by the board to finish the term of Gavin Newsom, who resigned to take office as Lieutenant Governor of California. 
Because of its unique city-county status, local government exercises jurisdiction over property that would otherwise be located outside of its corporation limit. San Francisco International Airport, though located in San Mateo County, is owned and operated by the City and County of San Francisco. San Francisco also has a county jail complex located in San Mateo County, in an unincorporated area adjacent to San Bruno. San Francisco was also granted a perpetual leasehold over the Hetch Hetchy Valley and watershed in Yosemite National Park by the Raker Act in 1913. 
San Francisco serves as the regional hub for many arms of the federal bureaucracy, including the U.S. Court of Appeals, the Federal Reserve Bank, and the U.S. Mint. Until decommissioning in the early 1990s, the city had major military installations at the Presidio, Treasure Island, and Hunters Point —a legacy still reflected in the annual celebration of Fleet Week. The State of California uses San Francisco as the home of the state supreme court and other state agencies. Foreign governments maintain more than seventy consulates in San Francisco. 
The municipal budget for fiscal year 2015–16 was $8.99 billion,  and is one of the largest city budgets in the United States.  The City of San Francisco spends more per resident than any city other than Washington D.C, over $10,000 in FY 2015–2016.  The city employs around 27,000 workers. 
The following table includes the number of incidents reported and the rate per 1,000 persons for each type of offense.
|Population and crime rates (2012)|
|Murder and nonnegligent manslaughter||69||0.08|
|Motor vehicle theft||5,339||6.51|
In 2011, 50 murders were reported, which is 6.1 per 100,000 people.  There were about 134 rapes, 3,142 robberies, and about 2,139 assaults. There were about 4,469 burglaries, 25,100 thefts, and 4,210 motor vehicle thefts.  The Tenderloin area has the highest crime rate in San Francisco: 70% of the city's violent crimes, and around one-fourth of the city's murders, occur in this neighborhood. The Tenderloin also sees high rates of drug abuse, gang violence, and prostitution.  Another area with high crime rates is the Bayview-Hunters Point area. In the first six months of 2015 there were 25 murders compared to 14 in the first six months of 2014. However, the murder rate is still much lower than in past decades.  That rate, though, did rise again by the close of 2016. According to the San Francisco Police Department, there were 59 murders in the city in 2016, an annual total that marked a 13.5% increase in the number of homicides (52) from 2015. 
Several street gangs operate in the city, including MS-13,  the Sureños and Norteños in the Mission District,.  African-American street gangs familiar in other cities, including the Crips, have struggled to establish footholds in San Francisco,  while police and prosecutors have been accused of liberally labeling young African-American males as gang members.  Criminal gangs with shotcallers in China, including Triad groups such as the Wo Hop To, have been reported active in San Francisco.  In 1977, an ongoing rivalry between two Chinese gangs led to a shooting attack at the Golden Dragon restaurant in Chinatown, which left 5 people dead and 11 wounded. None of the victims in this attack were gang members. Five members of the Joe Boys gang were arrested and convicted of the crime.  In 1990, a gang-related shooting killed one man and wounded six others outside a nightclub near Chinatown.  In 1998, six teenagers were shot and wounded at the Chinese Playground; a 16-year-old boy was subsequently arrested. 
The San Francisco Police Department was founded in 1849.  The portions of Golden Gate National Recreation Area located within the city, including the Presidio and Ocean Beach, are patrolled by the United States Park Police.
Colleges and universities
The University of California, San Francisco is the sole campus of the University of California system entirely dedicated to graduate education in health and biomedical sciences. It is ranked among the top five medical schools in the United States  and operates the UCSF Medical Center, which ranks as the number one hospital in California and the number 5 in the country.  UCSF is a major local employer, second in size only to the city and county government.    A 43-acre (170,000 m 2) Mission Bay campus was opened in 2003, complementing its original facility in Parnassus Heights. It contains research space and facilities to foster biotechnology and life sciences entrepreneurship and will double the size of UCSF's research enterprise.  All in all, UCSF operates more than 20 facilities across San Francisco.  The University of California, Hastings College of the Law, founded in Civic Center in 1878, is the oldest law school in California and claims more judges on the state bench than any other institution.  San Francisco's two University of California institutions have recently formed an official affiliation in the UCSF/UC Hastings Consortium on Law, Science & Health Policy. 
San Francisco State University is part of the California State University system and is located near Lake Merced.  The school has approximately 30,000 students and awards undergraduate, master's and doctoral degrees in more than 100 disciplines.  The City College of San Francisco, with its main facility in the Ingleside district, is one of the largest two-year community colleges in the country. It has an enrollment of about 100,000 students and offers an extensive continuing education program. 
Founded in 1855, the University of San Francisco, a private Jesuit university located on Lone Mountain, is the oldest institution of higher education in San Francisco and one of the oldest universities established west of the Mississippi River.  Golden Gate University is a private, nonsectarian, coeducational university formed in 1901 and located in the Financial District. With an enrollment of 13,000 students, the Academy of Art University is the largest institute of art and design in the nation.  Founded in 1871, the San Francisco Art Institute is the oldest art school west of the Mississippi.  The California College of the Arts, located north of Potrero Hill, has programs in architecture, fine arts, design, and writing.  The San Francisco Conservatory of Music, the only independent music school on the West Coast, grants degrees in orchestral instruments, chamber music, composition, and conducting. The California Culinary Academy, associated with the Le Cordon Bleu program, offers programs in the culinary arts, baking and pastry arts, and hospitality and restaurant management. California Institute of Integral Studies, founded in 1968, offers a variety of graduate programs in its Schools of Professional Psychology & Health, and Consciousness and Transformation.
Primary and secondary schools
Public schools are run by the San Francisco Unified School District as well as the State Board of Education for some charter schools. Lowell High School, the oldest public high school in the U.S. west of the Mississippi,  and the smaller School of the Arts High School are two of San Francisco's magnet schools at the secondary level. Public school students attend schools based on an assignment system rather than neighborhood proximity. 
Just under 30% of the city's school-age population attends one of San Francisco's more than 100 private or parochial schools, compared to a 10% rate nationwide.  Nearly 40 of those schools are Catholic schools managed by the Archdiocese of San Francisco. 
San Francisco has nearly 300 preschool programs primarily operated by Head Start, San Francisco Unified School District, private for-profit, private non-profit and family child care providers.  All 4-year old children living in San Francisco are offered universal access to preschool through the Preschool for All program. 
The major daily newspaper in San Francisco is the San Francisco Chronicle, which is currently Northern California's most widely circulated newspaper.  The Chronicle is most famous for a former columnist, the late Herb Caen, whose daily musings attracted critical acclaim and represented the "voice of San Francisco". The San Francisco Examiner, once the cornerstone of William Randolph Hearst's media empire and the home of Ambrose Bierce, declined in circulation over the years and now takes the form of a free daily tabloid, under new ownership.   Sing Tao Daily claims to be the largest of several Chinese language dailies that serve the Bay Area.  SF Weekly is the city's alternative weekly newspaper. San Francisco Magazine and 7x7 are major glossy magazines about San Francisco. The national newsmagazine Mother Jones is also based in San Francisco.
The San Francisco Bay Area is the sixth-largest television market  and the fourth-largest radio market  in the U.S. The city's oldest radio station, KCBS (AM), began as an experimental station in San Jose in 1909, before the beginning of commercial broadcasting. KALW was the city's first FM radio station when it signed on the air in 1941. The city's first television station was KPIX, which began broadcasting in 1948.
All major U.S. television networks have affiliates serving the region, with most of them based in the city. CNN, MSNBC, BBC, Al Jazeera America, Russia Today, and CCTV America also have regional news bureaus in San Francisco. Bloomberg West was launched in 2011 from a studio on the Embarcadero and CNBC broadcasts from One Market Plaza since 2015. ESPN uses the local ABC studio for their broadcasting. The regional sports network, Comcast SportsNet Bay Area and its sister station Comcast SportsNet California, are both located in San Francisco. The Pac-12 Network is also based in San Francisco.
Public broadcasting outlets include both a television station and a radio station, both broadcasting under the call letters KQED from a facility near the Potrero Hill neighborhood. KQED-FM is the most-listened-to National Public Radio affiliate in the country.  Another local broadcaster, KPOO, is an independent, African-American owned and operated noncommercial radio station established in 1971.  CNET, founded 1994, and Salon.com, 1995, are based in San Francisco.
San Francisco-based inventors made important contributions to modern media. During the 1870s, Eadweard Muybridge began recording motion photographically and invented a zoopraxiscope with which to view his recordings. These were the first motion pictures. Then in 1927, Philo Farnsworth's image dissector camera tube transmitted its first image. This was the first television.
Freeways and roads
Due to its unique geography, and the freeway revolts of the late 1950s,  Interstate 80 begins at the approach to the Bay Bridge and is the only direct automobile link to the East Bay. U.S. Route 101 connects to the western terminus of Interstate 80 and provides access to the south of the city along San Francisco Bay toward Silicon Valley. Northward, the routing for U.S. 101 uses arterial streets to connect to the Golden Gate Bridge, the only direct automobile link to Marin County and the North Bay.
State Route 1 also enters San Francisco from the north via the Golden Gate Bridge and bisects the city as the 19th Avenue arterial thoroughfare, joining with Interstate 280 at the city's southern border. Interstate 280 continues south from San Francisco, and also turns to the east along the southern edge of the city, terminating just south of the Bay Bridge in the South of Market neighborhood. After the 1989 Loma Prieta earthquake, city leaders demolished the Embarcadero Freeway and a portion of the Central Freeway, converting them into street-level boulevards. 
State Route 35 enters the city from the south as Skyline Boulevard and terminates at its intersection with Highway 1. State Route 82 enters San Francisco from the south as Mission Street, and terminates shortly thereafter at its junction with 280.
32% of San Francisco residents use public transportation in daily commuting to work, ranking it first on the West Coast and third overall in the United States.  The San Francisco Municipal Railway, known as Muni, is the primary public transit system of San Francisco. Muni is the seventh-largest transit system in the United States, with 210,848,310 rides in 2006.  The system operates both a combined light rail and subway system, the Muni Metro, and a large bus network.  Additionally, it runs a historic streetcar line, which runs on Market Street from Castro Street to Fisherman's Wharf.  It also operates the famous cable cars,  which have been designated as a National Historic Landmark and are a major tourist attraction. 
Bay Area Rapid Transit, a regional Rapid Transit system, connects San Francisco with the East Bay through the underwater Transbay Tube. The line runs under Market Street to Civic Center where it turns south to the Mission District, the southern part of the city, and through northern San Mateo County, to the San Francisco International Airport, and Millbrae. 
Another Commuter Rail system, Caltrain, runs from San Francisco along the San Francisco Peninsula to San Jose.  Historically, trains operated by Southern Pacific Lines ran from San Francisco to Los Angeles, via Palo Alto and San Jose.
Amtrak California Thruway Motorcoach runs a shuttle bus from San Francisco to its rail station across the Bay in Emeryville.  Lines from Emeryville Station include the Capitol Corridor, San Joaquin, California Zephyr, and Coast Starlight. Thruway service also runs south to San Luis Obispo, California with connection to the Pacific Surfliner.
San Francisco Bay Ferry operates from the Ferry Building and Pier 39 to points in Oakland, Alameda, Bay Farm Island, South San Francisco, and north to Vallejo in Solano County.  The Golden Gate Ferry is the other ferry operator with service between San Francisco and Marin County.  Soltrans runs supplemental bus service between the Ferry Building and Vallejo.
To accommodate the large amount of San Francisco citizens who commute to the Silicon Valley daily, companies like Google and Apple have begun to provide private bus transportation for their employees, from San Francisco locations to the tech start-up hotspot. These buses have quickly become a heated topic of debate within the city, as protesters claim they block bus lanes and delay public buses. 
Though located 13 miles (21 km) south of downtown in unincorporated San Mateo County, San Francisco International Airport (SFO) is under the jurisdiction of the City and County of San Francisco. SFO is a hub for United Airlines  and Virgin America.  SFO is a major international gateway to Asia and Europe, with the largest international terminal in North America.  In 2011, SFO was the 8th busiest airport in the U.S. and 22nd busiest in the world, handling over 40.9 million passengers. 
Located across the bay, Oakland International Airport is a popular, low-cost alternative to SFO. Geographically, Oakland Airport is approximately the same distance from downtown San Francisco as SFO, but due to its location across San Francisco Bay, it is greater driving distance from San Francisco.
Cycling and walking
Cycling is a popular mode of transportation in San Francisco. 75,000 residents commute by bicycle per day.  Bay Area Bike Share launched in August 2013 with 700 bikes in downtown San Francisco and selected cities south to San Jose. The San Francisco Municipal Transportation Agency and Bay Area Air Quality Management District are responsible for the operation with management provided by Alta Bicycle Share.  The system will be expanded in the future.  Pedestrian traffic is a major mode of transport. In 2015, ranked San Francisco the second-most walkable city in the United States.   
San Francisco has significantly higher rates of pedestrian and bicyclist traffic deaths than the United States on average. In 2013, 21 pedestrians were killed in vehicle collisions, the highest since 2001,  which is 2.5 deaths per 100,000 population – 70% higher than the national average of 1.5 deaths per 100,000 population. 
Cycling is growing in San Francisco. Annual bicycle counts conducted by the Municipal Transportation Agency (MTA) in 2010 showed the number of cyclists at 33 locations had increased 58% from the 2006 baseline counts.  In 2008, the MTA estimated that about 128,000 trips were made by bicycle each day in the city, or 6% of total trips.  Since 2002, improvements in cycling infrastructure in recent years, including additional bike lanes and parking racks, have made cycling in San Francisco safer and more convenient.  Since 2006, San Francisco has received a Bicycle Friendly Community status of "Gold" from the League of American Bicyclists. 
San Francisco as a Global City
According to academic Rob Wilson, San Francisco is a global city, a status that pre-dated the city's popularity during the California Gold Rush.  Such cities are characterized by their ethnic clustering, network of international connectivity, and convergence of technological innovation.  Global cities, such as San Francisco, are considered to be complex and require a high level of talent as well as large masses of low wage workers. A divide is created within the city of ethnic, typically lower-class neighborhoods, and expensive ones. This in turn creates a population of highly educated intellectuals and immigrants who both are drawn to the increasing number of opportunities available.  Competition for these opportunities pushes growth and adaptation in world centers.  San Francisco is home to many of the world's largest high tech corporations, which offer such opportunities. They are part of the greater Silicon Valley, which encompasses much of the Bay area and surrounding cities. 
Ethnic neighborhoods in global cities offer immigrants a smooth transition into their new country. Language proficiency allows immigrants to navigate their new environment effectively, reducing stress caused by adaptation into the new city.  Immigrant groups concentrate in these neighborhoods because of the rich social infrastructure and culture that is unavailable to them elsewhere in the new country. 
San Francisco has several prominent Chinese, Mexican, and Filipino ethnic neighborhoods including Chinatown and the Mission District. Research collected on the immigrant clusters in the city show that more than half of the Asian population in San Francisco is either Chinese born (40.3%) or Philippine born (13.1%), and of the Mexican population 21% were Mexican born, meaning these are people who recently immigrated to the United States.  Between the years of 1990 and 2000, the number foreign born residents increased from 33% to nearly 40%.  During this same time period, the San Francisco Metropolitan area received 850,000 immigrants, ranking third in the United States after Los Angeles and New York. 
San Francisco became a hub for technological driven economic growth during the internet boom of the 1990s, and still holds an important position in the world city network today. Intense redevelopment towards the " new economy " makes business more technologically minded. Between the years of 1999 and 2000, the job growth rate was 4.9%, creating over 50,000 jobs in technology firms and internet content production.
In the second technological boom driven by social media in the mid 2000s, San Francisco became a popular location for companies such as Apple, Google, Facebook and Twitter to base their tech offices and for their employees to live.  Since then, tech employment has continued to increase. In 2014, San Francisco’s tech employment grew nearly 90% between 2010 and 2014, beating out Silicon Valley ’s 30% growth rate over the same period. 
The tech sector’s dominance in the Bay Area is internationally recognized and continues to attract new businesses and young entrepreneurs from all over the globe . San Francisco is now widely considered the most important city in the world for new technology startups . A recent high of 7 billion dollars in venture capital was invested in the region.  These startup companies hire a high concentration of bright intellectuals looking to work in the tech industry, and creates a city population of highly concentrated levels of intelligence. Over 50% of San Franciscans have a 4 year university degree, ranking the city among the highest levels of education in the country and world. 
Immigrants in the Workforce
In the global economy, San Francisco’s diverse population is claimed to be one of its strongest assets.  Just as in other global cities, the San Francisco economy relies on its polarized labor structure. This structure includes highly educated immigrants working in the high end occupational spectrum, such as the dot-com sector, as well as poorly educated, low skilled immigrants who work in the low paying service sector. The different ethnic communities within San Francisco gives the city connections to important markets around the world, and increases its global reputation. However, issues such as skyrocketing housing costs have caused much of the working and middle classes, including immigrants, to be expelled from the city. 
Consulates and sister cities
(not including other types of municipal partnerships such as "friendship cities")
- Abidjan, Cote d'Ivoire
- Amman, Jordan
- Assisi, Umbria, Italy
- Barcelona, Spain
- Bangalore, India
- Cork, Ireland
- Haifa, Israel
- Ho Chi Minh City, Vietnam
- Kraków, Poland
- Manila, Philippines
- Paris, France
- Seoul, South Korea
- Shanghai, China
- Sydney, Australia
- Taipei, Taiwan
- Thessaloniki, Greece
- Zürich, Switzerland
- Architecture of San Francisco
- California earthquake forecast
- Gold Mountain (Chinese name for part of North America)
- List of cities and towns in California
- List of cities and towns in the San Francisco Bay Area
- List of counties in California
- List of largest California cities by population
- Ships lost in San Francisco
- The coordinates of the station are. Precipitation, high temperature, low temperature, snow, and snow depth records date from 1 October 1849, 1 June 1874, 1 January 1875, 1 January 1876, and 1 January 1922, respectively.
- Mean monthly maxima and minima (i.e. the expected highest and lowest temperature readings at any point during the year or given month) calculated based on data at said location from 1981 to 2010.