Autumn begins astronomically in the Northern Hemisphere on September 22, 2025, at 2:19 p.m. EDT. While the equinox is often described as having equal day and night, this is a simplification. Atmospheric refraction and the sun's apparent size cause daylight to be longer than 12 hours even on the equinox. This effect is particularly pronounced at higher latitudes, with the North Pole experiencing a much shorter period of total darkness than the common misconception of six months.

Prepared by Olivia Bennett and reviewed by editorial team.