Fall Equinox Day 2025 Date. London the exact moment of the autumnal equinox in 2025 is 22. The autumnal equinox is an astronomical event that occurs on september 22nd every year.

The first day of fall 2025 arrives with the fall equinox on monday, september 22, 2025, 2:19 p.m. In different time zones, the date of the equinox may differ by a day, so it is important to indicate your exact location.