Autumnal Equinox 2024

Autumnal Equinox 2024. The equinoxes occur around march 20 and september 22 each year, corresponding to an equal length of day and. Falling on september 22, 2024, this equinox marks the official start of fall in the northern hemisphere.

Though the autumnal equinox is often referred to as the “first day of fall,” there are different ways to define the. Autumnal equinox — is an astronomical phenomenon, when the sun in its visible motion along the ecliptic crosses the celestial equator.