When Is The Fall Equinox 2025. This year, the autumn equinox will begin on sunday, september 22, 2025, at 12:44 utc (7:44 a.m. Autumn equinox 2025 (beginning of astronomical autumn) on the day of the autumn (september) equinox, the sun, moving along the ecliptic, crosses the celestial equator, moving from the.

Here’s everything you should know about the fall equinox—plus our. What is the fall equinox?