What Day Is The Autumn Equinox In 2024. On that day, the autumnal equinox will occur, marking the beginning of fall. The autumn equinox marks the start of the season, meaning it’ll take place on september 22 this year.
This year autumn begins on 23 september 2023 and ends on 22 december 2023. In 2024, the last day of summer in the northern hemisphere is september 22!