22 September 2025
Today the autumnal equinox will occur at 2:19pm Eastern Daylight Time (6:19pm UTC) at the moment when the sun crosses the equator heading southward. From outer space exactly half the globe is lit north-to-south as shown in this NOAA GOES 16 weather satellite image from 2022. (Notice Hurricane Ian spinning in the Atlantic in this photo.)
Solstice and equinox were a big deal in ancient cultures. The Chaco Culture National Historical Park in New Mexico, built by Hopi and Pueblo peoples between AD 900 and 1150, has many structures that align with astronomical events including the equinox sunrise, pictured at top, which draws visitors to see it.
Modern structures sometimes align with the equinox sunset, though unintentionally, because the streets are built east-west. This stacked and cropped photo of the equinox sunset view on Chicago’s 53rd Street is sometimes called “Chicagohenge.”
When we lived in Greenfield we experienced the same effect. The closely spaced houses on my street faced due west (rare in Pittsburgh!) and lined up so that the rays of sunset at the equinox fell directly between the buildings without touching the side walls of the houses.
Do you have a favorite place to note the equinox? Today’s the day to watch it at sunset.