Fall Starts 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. All updates will be reflected here with the date of change noted.
Fall will last until december 22, which is when winter starts. The autumnal equinox—the september equinox or the fall equinox—arrives on sunday, september 22.