Autumn Equinox Southern Hemisphere 2024 Date. In the northern hemisphere the autumnal equinox falls about september 22 or 23, as the sun crosses the celestial equator going south. The specific time, in the case of this year 8:43 a.m.

On the day of the autumn (september) equinox, the sun, moving along the ecliptic, crosses the celestial equator, moving from the northern hemisphere to the southern. This event marks the beginning of spring in the northern hemisphere and autumn in the southern hemisphere.