Autumnal Equinox 2024 Usa Central Time Map. Autumnal equinox — is an astronomical phenomenon, when the sun in its visible motion along the ecliptic crosses the celestial equator. The autumnal equinox (as well as spring equinox) is the moment when neither of the earth’s hemispheres is inclined towards or away from the sun.

The autumnal equinox for the northern hemisphere and the first day of fall begin on the same day, at 8:44 a.m. Summer begins with the summer solstice, thursday, june 20, 2024, 4:51 p.m.