First Day Of Fall 2025 Usa. The first day of fall this year, also known as the autumnal equinox is sunday, sept. In the northern hemisphere, the fall months are from the end of september, through october and.
When is the autumnal equinox? Autumn 2025 starts on sunday, 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.