when is the autumnal equinox 2025

The autumnal equinox in 2025 occurs on Monday, September 22. Specifically, it will happen at 18:19 UTC (which is 19:19 BST or 2:19 p.m. EDT), marking the moment when day and night are approximately equal in length and astronomical autumn begins in the Northern Hemisphere. This is the time when the Sun crosses the celestial equator moving southward, signaling the start of fall in the north and spring in the Southern Hemisphere.