Autumnal Equinox 2026

First Day of Autumn (Northern Hemisphere)

September 23, 2026 at 00:05 (UTC)

The Autumnal Equinox 2026 in the Northern Hemisphere occurs on Wednesday, September 23, at 00:05 UTC. This astronomical event marks the official start of autumn, when the Sun crosses the celestial equator, leading to roughly equal day and night across the globe.