Nation The autumnal equinox marks the end of summer. But is it the start of fall or autumn? September 22, 2021 Keira Wingate, USA TODAY Comments Off on The autumnal equinox marks the end of summer. But is it the start of fall or autumn? As summer comes to an end, the next season starts. 'Fall' and 'autumn' are the two words to describe the breezy season, but which is most accurate?