In 2022, the autumnal equinox—also called the September equinox or fall equinox—arrives on Thursday, September 22. This date marks the start of fall in the Northern Hemisphere and spring in the Southern Hemisphere.
For those in the Northern Hemisphere, when the Sun crosses the equator going from north to south, this marks the autumnal equinox. This equinoxes provide Earth with roughly 12 hours of daylight and 12 hours of darkness. Days become shorter than nights as the Sun continues to rise later and nightfall arrives earlier.