fall

Fall, also known as autumn, is one of the four temperate seasons. It marks the transition from warmer to cooler weather and from long to shorter days as the tilt of Earth’s axis away from the sun reduces solar heating. In the Northern Hemisphere, fall generally spans from late September to late December, with the autumnal equinox around September 22 or 23. In the Southern Hemisphere, the season occurs roughly from late March to late June. In tropical regions, fall is not a distinct season and weather patterns are driven by other climatic cycles.

The naming of the season varies by region: fall is common in American and Canadian English and derives from the falling of leaves and fruit, while autumn is standard in British English and many other varieties of English. Both terms refer to the same period.

Typical features include cooler temperatures, shorter days, and often brisk winds. Deciduous trees shed their leaves, producing colorful displays as chlorophyll breaks down and other pigments become visible. Agricultural activity centers on harvest, and many crops reach maturity in autumn.

In many ecosystems, animals prepare for winter, with migrations and changes in behavior. Culturally, autumn is associated with harvest and related festivals. In the United States and Canada, Halloween is celebrated on October 31, and Thanksgiving holidays reflect seasonal themes, with variations in timing and customs across regions.