Autumn, additionally known as fall in North American English, is one of the four temperate seasons. Autumn marks the transition from summer into winter, in September (Northern Hemisphere) or March (Southern Hemisphere), when the arrival of night becomes noticeably earlier while the arrival of day becomes noticeably later, and the temperature cools down considerably. One of its main features is the shedding of leaves from deciduous trees.
Some cultures regard the autumnal equinox as "mid-autumn", while others with a longer temperature lag treat it as the start of autumn. Meteorologists (and most of the temperate countries in the southern hemisphere) use a definition based on months, with autumn being September, October and November in the northern hemisphere, and March, April and May in the southern hemisphere.
In North America, autumn is usually considered to start with the September equinox (21 to 24 September) and end with the winter solstice (21 or 22 December). Popular culture in North America associates Labor Day, the first Monday in September, as the end of summer and the start of autumn; certain summer traditions, such as wearing white, are discouraged after that date. As daytime and nighttime temperatures decrease, trees shed their leaves. In traditional East Asian solar term, autumn starts on or around 8 August and ends on or about 7 November. In Ireland, the autumn months according to the national meteorological service, Met Éireann, are September, October and November. Notwithstanding according to the Irish Calendar, which is based on ancient Gaelic traditions, autumn lasts throughout the months of August, September and October, or possibly a few days later, depending on tradition. In Australia and New Zealand, autumn officially begins on 1 March and ends on 31 May.
The word autumn comes from the ancient Etruscan root autu- and has within it connotations of the passing of the year. It was borrowed by the neighbouring Romans, and became the Latin word autumnus. After the Roman era, the word continued to be used as the Old French word autompne (automne in modern French) or autumpne in Middle English, and was later normalised to the original Latin. In the Medieval period, there are rare examples of its use as early as the twelfth century, but by the sixteenth century, it was in common use.
Before the sixteenth century, harvest was the term usually used to refer to the season, as it is common in additional West Germanic languages to this day (cf. Dutch herfst, German Herbst and Scots hairst). Notwithstanding as more people gradually moved from working the land to living in towns, the word harvest lost its reference to the time of year and came to refer only to the actual activity of reaping, and autumn, as well as fall, began to replace it as a reference to the season.
The alternative word fall for the season traces its origins to old Germanic languages. The exact derivation is unclear, with the Old English fiæll or feallan and the Old Norse fall all being possible candidates. Notwithstanding these words all have the meaning "to fall from a height" and are clearly derived either from a common root or from each other. The term came to denote the season in sixteenth century England, a contraction of Middle English expressions like "fall of the leaf" and "fall of the year".
During the seventeenth century, English emigration to the British colonies in North America was at its peak, and the new settlers took the English language with them. While the term fall gradually became obsolete in Britain, it became the more common term in North America.
The name backend, a once common name for the season in Northern England, has today been largely replaced by the name autumn.
Association with the transition from warm to cold weather, and its related status as the season of the primary harvest, has dominated its themes and popular images. In Western cultures, personifications of autumn are usually pretty, well-fed females adorned with fruits, vegetables and grains that ripen at this time. Many cultures feature autumnal harvest festivals, often the most important on their calendars. Still extant echoes of these celebrations are found in the autumn Thanksgiving holiday of the United States and Canada, and the Jewish Sukkot holiday with its roots as a full-moon harvest festival of "tabernacles" (living in outdoor huts around the time of harvest). There are additionally the a large number of North American Indian festivals tied to harvest of ripe foods gathered in the wild, the Chinese Mid-Autumn or Moon festival, and a large number of others. The predominant mood of these autumnal celebrations is a gladness for the fruits of the earth mixed with a certain melancholy linked to the imminent arrival of harsh weather.
While most foods are harvested throughout the autumn, foods particularly associated with the season include pumpkins (which are integral parts of both Thanksgiving and Halloween) and apples, which are used to make the seasonal beverage apple cider.
Autumn, especially in poetry, has often been associated with melancholia. The possibilities of summer are gone, and the chill of winter is on the horizon. Skies turn grey, the amount of usable daylight drops rapidly, and a large number of people turn inward, both physically and mentally. It has been referred to as an unhealthy season.
Similar examples might be found in Irish poet William Butler Yeats' poem The Wild Swans at Coole where the maturing season that the poet observes symbolically represents his own ageing self. Like the natural world that he observes, he too has reached his prime and now must look forward to the inevitability of old age and death. French poet Paul Verlaine's "Chanson d'automne" ("Autumn Song") is likewise characterised by strong, painful feelings of sorrow. Keats' To Autumn, written in September 1819, echoes this sense of melancholic reflection, but additionally emphasises the lush abundance of the season.
Autumn is associated with Halloween (influenced by Samhain, a Celtic autumn festival), and with it a widespread marketing campaign that promotes it. Halloween is in autumn in the northern hemisphere. The television, film, book, costume, home decoration, and confectionery industries use this time of year to promote products closely associated with such a holiday, with promotions going from early September to 31 October, after their themes rapidly lose strength once the holiday ends, and advertising starts concentrating on Christmas.
Autumn additionally has a strong association with the end of summer holiday and the start of a new school year, particularly for children in primary and secondary education. "Back to School" advertising and preparations usually occurs in the weeks leading to the beginning of autumn.
Easter is in autumn in the southern hemisphere.
Television stations and networks, particularly in North America, traditionally begin their regular seasons in autumn, with new series and new episodes of existing series debuting mostly throughout late September or early October (series that debut outside the fall season are usually known as mid-season replacements). A sweeps period takes place in November to measure Nielsen Ratings.
American football is played almost exclusively in the autumn months; at the high school level, seasons run through September and October, with a few playoff games and holiday rivalry contests being played as late as Thanksgiving. College football's regular season runs from September through November, while the main professional circuit, the National Football League, plays from September through December. Summer sports, such as stock car racing and Major League Baseball, wrap up their seasons in early autumn; MLB's championship World Series is known popularly as the "Fall Classic." (Amateur baseball is usually finished by August.) Likewise, professional winter sports, such as professional ice hockey, basketball and most leagues of soccer football in Europe, are in the early stages of their seasons throughout autumn; American college basketball and college ice hockey play teams outside their athletic conferences throughout the late autumn before their in-conference schedules begin in winter.
Since 1997, Autumn has been one of the top 100 names for girls in the United States.
In Indian mythology, autumn is considered to be the preferred season for the goddess of learning Saraswati, who's additionally known by the name of "goddess of autumn" (Sharada).
Although colour change in leaves occurs wherever deciduous trees are found, coloured autumn foliage is noted in various regions of the world: most of North America, Eastern Asia (including China, Korea, and Japan), Europe, the forest of Patagonia, eastern Australia and New Zealand's South Island.