autumns

Autumn, or autumns when referred to in plural, is one of the four temperate seasons that follow summer and precede winter. In common use, the term autumn contrasts with fall, the North American term for the same season. The word autumn originates from Old French automne and from Latin autumnus; the exact origin is uncertain, but it has long been associated with the harvest.

In climate terms, autumn is characterized by cooling temperatures and shorter days as the Sun's path lowers in the sky. In many regions, deciduous trees shed leaves, producing color changes from green to red, orange, and yellow as chlorophyll breaks down. Precipitation patterns vary, with some areas experiencing increased rainfall, while others become drier.

Calendars define autumn in different ways. Astronomical autumn begins with the autumnal equinox, when day and night are of approximately equal length, and ends at the winter solstice. Meteorological autumn is defined as September, October, and November in the Northern Hemisphere. In the Southern Hemisphere, autumn is roughly March through May, corresponding to the opposite seasons.

Human activities and culture reflect autumn's seasonal changes. Harvest traditions and festivals appear in many cultures, including Thanksgiving in parts of North America and Harvest festivals in other regions. Halloween is associated with autumn in many countries. Autumn imagery appears in literature, art, and music.