First Day Of Fall 2025 Time. The first day of winter in the northern hemisphere is marked by the winter solstice, which is expected to arrive at 3:19 a.m. This year, the autumnal equinox falls on sept.
The first day of fall, also known as the autumnal equinox, is sunday, sept. The first day of autumn, known for the equinox, has roots that stretch back through history and across cultures.