According to the astronomical definition, fall begins with the autumnal equinox. In the Northern Hemisphere, it's the September equinox; south of the equator, it is the equinox in March.

Sep 10, 2025 · The fall equinox and the first day of autumn arrive on Monday, September 22, 2025, at 2:19 P.M. EDT in the Northern Hemisphere. The equinox occurs at the same moment …

Sep 18, 2017 · The fall equinox is not on the same day each year, though it always falls between September 21 and September 24.

Oct 10, 2025 · In the Northern Hemisphere the autumnal equinox falls about September 22 or 23, as the Sun crosses the celestial equator going south. In the Southern Hemisphere the equinox …

Sep 22, 2025 · The autumnal equinox occurs on Monday, September 22, at 2:19 P.M. ET in the Northern Hemisphere. Daylight saving time will end on Sunday, November 2, 2025, when …

Sep 20, 2025 · Because the Fall Equinox is not a fixed day but is rather based on an astronomical prediction, the date can change from year to year. But it always occurs between September 21 …

Sep 21, 2025 · Fall begins in the Northern Hemisphere on Monday, Sept. 22, when Earth experiences equal day and night, known as the autumnal equinox.

Sep 3, 2025 · The fall equinox will occur on September 22, 2025, in the Northern Hemisphere, marking the official start of autumn. In the Southern Hemisphere, the next fall equinox will …

Sep 16, 2025 · The autumn equinox marks the end of summer and the beginning of fall in the Northern Hemisphere. In 2025, the first day of fall will be Monday, Sept. 22.

Sep 19, 2025 · A carefully worded answer is that on Monday, Sept. 22, at 2:19 p.m. Eastern daylight time (11:19 a.m. Pacific daylight time) autumn begins astronomically in the Northern …