Fall Equinox Day 2025 Date. Autumn 2025 starts on monday, september 22nd in the northern hemisphere, with daylight time shortening and the leaves begining to fall with the changing tilt of the earth's axis. The first day of fall, also known as the autumnal equinox, in 2025 will be on september 23rd.
First day of fall in 2025 is on monday, the 22nd of september (22/9/2025). Autumn 2025 starts on monday, september 22nd in the northern hemisphere, with daylight time shortening and the leaves begining to fall with the changing tilt of the earth’s axis.