Autumnal Equinox
September 22 is the date of the autumnal equinox, the day that astronomical summer ends and astronomical autumn begins in the northern hemisphere. On that day the sun rises exactly due east and sets exactly due west. It’s also a day with approximately equal amounts of daylight and darkness. Moving forward, we will experience less and less daylight until we reach the minimum amount on the winter solstice a few days before Christmas. And then the pattern reverses as we continue our annual journey around the Sun.
Understanding the Autumnal Equinox and Seasonal Changes in Daylight
