The autumnal equinox arrives Monday, September 23, 2022.
WHEN DO THE SEASONS OF THE YEAR BEGIN?
Listed below are the equinox and solstice dates and times, based on the Eastern Time Zone (ET). Adjust to your time zone. Note that an almanac is an astronomical "calendar of the heavens;" these dates are not based on local meteorology.
For readers of The Old Farmer's Almanac, these dates mark the start of the spring, summer, autumn and winter seasons in the Northern Hemisphere.
Please Note: The times are based on Eastern time. Subtract 3 hours for Pacific time, 2 hours for Mountain time, 1 hour for Central time, or whatever is relevant to your time zone.
AUTUMNAL EQUINOX DATES AND TIMES
Year Autumnal Equinox (Northern Hemisphere)
2020 Tuesday, September 22
2021 Wednesday, September 22
2022 Thursday, September 22
2023 Friday, September 22
WHY DO THE SEASONS CHANGE?
The four seasons are determined by shifting sunlight (not heat!) --- which is determined by how our planet orbits the Sun and the tilt of its axis.
On the autumnal equinox, day and night are each about 12 hours long (with the actual time of equal day and night, in the Northern Hemisphere, occurring a few days after the autumnal equinox). The Sun crosses the celestial equator going southward; it rises exactly due east and sets exactly due west. See our First Day of Fall page.