1st Day Of Autumn 2024 Date And Time. Ct december 21 in 2024, according to. Autumn 2024 starts on 1 september meteorologically and on 22 september astronomically.

The autumn equinox is due to commence at 08:44 et/05:44 pt in the northern hemisphere and takes place at the same time across the globe, regardless of. Learn what the autumnal equinox is, when it happens, and why it marks the start of fall in the northern hemisphere.