Fall Equinox 2024 Usa. The september equinox marks the beginning of fall in the northern hemisphere and the first day of spring in the southern hemisphere. The date varies slightly year to year, but it is usually september 22 or 23.

Summer begins with the summer solstice, thursday, june 20, 2024, 4:51 p.m. Because the fall equinox is not a fixed day but is rather based on an.