What Month Is Autumn 2024. This online date calculator will help you calculate how many days are left until any holiday. In 2024, the autumnal (fall) equinox arrives on sunday, september 22, marking the official first day of fall.

The astronomical calendar determines the seasons due to the 23.5. The autumnal equinox occurs in september each year, and in the northern hemisphere the date marks the end of summer and beginning of autumn.