when is autumn 2023

Autumn in 2023 began on Saturday, 23 September 2023, according to the astronomical definition. This marks the autumnal equinox, when day and night are approximately equal in length. The season then ended on Friday, 22 December 2023. Meteorologically, autumn is defined as starting earlier, on 1 September and ending on 30 November 2023. The exact time of the astronomical start of autumn in 2023 was 6:50 AM GMT (7:50 AM BST in the UK) on 23 September. This equinox occurs when the sun crosses the celestial equator going southward, marking the start of autumn in the Northern Hemisphere.