When Is Autumnal Equinox 2025. The time of fall is different for different parts of the world. In 2025 the autumnal equinox will occur on 22 september at 12.44pm gmt (1.44pm bst).
Autumnal equinox โ is an astronomical phenomenon, when the sun in its visible motion along the ecliptic crosses the celestial equator. The first day of fall in the northern hemisphere is sunday, sept.