Autumn Equinox 2025 Uk Calendar. Autumn equinox 2025 occurs sunday 22 september at 12:44pm (13:44 utc), as this is when the centre of the sun crosses the celestial equator. โ autumn 2025 begins on 22 september and ends on 21 december, according to the astronomical calendar.
Eastern daylight time (5:44 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,.