Autumn Equinox 2025 Est. 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. Time to go out to connect and to have fun.
Day and night have equal length, marking the beginning of autumn in the northern hemisphere and spring in the southern hemisphere. At the september equinox, the sun is moving from north to south as it crosses above the equator.