autumnal equinox

In 2023, the autumn equinox falls on Saturday, September 23.

The autumnal equinox (sometimes called the September equinox or southward equinox) is the moment when the Sun appears to cross the celestial equator, heading southward. Due to differences between the calendar year and the tropical year, the September equinox may occur anytime from September 21 to 24.

The autumnal equinox (sometimes called the September equinox or southward equinox) is the moment when the Sun appears to cross the celestial equator, heading southward. Due to differences between the calendar year and the tropical year, the September equinox may occur anytime from September 21 to 24.