September 22, 2021
The 2021 fall equinox occurs today at 2:14 pm. This occurs when the Sun crosses Earth’s celestial equator at its descending node. After today, the Sun will appear lower in the sky each day until the winter solstice on December 21, 2021.
Earth seen during the autumnal equinox by the GOES East satellite on September 23, 2019. Image credit: NOAA.