What Day Is The First Day Of Fall 2025 In Usa. When the autumnal equinox arrives in september each year, we greet the arrival of the autumn season. The september or autumnal equinox is when the sun.

This year the autumn will start on sunday september 22, 2024 (day of the fall equinox) and will end on saturday december 21, 2024 with the winter solstice. Does spring begin on march 1?