Autumnal Equinox is also known as September Equinox or Southward Equinox. This observance marks the other end of astronomical summer and the beginning of fall or autumn season in the Northern Hemisphere, hence the name. To mark Autumnal Equinox 2023, Here are Happy Autumnal Equinox 2023 Greetings, Happy Autumnal Equinox Images and Wallpapers to share with family and friends.