New Delhi, Sept. 22 -- The autumnal equinox - the official start of fall in the Northern Hemisphere - will occur on Monday, September 22, 2025, at precisely 2:19 p.m. EDT, according to The Old Farmer's Almanac. This astronomical event takes place when the sun crosses the celestial equator, an imaginary line in the sky directly above Earth's equator.

Unlike solstices, which mark the longest and shortest days of the year, the equinox is unique in offering nearly equal hours of daylight and darkness across the globe. After the equinox, daylight steadily decreases until the winter solstice in December.

The equinox occurs twice each year - in September (autumnal) and March (vernal or spring). On these dates:

Earth's axis is tilted neither t...