What the equinox 'henge' effect tells us about U.S. cities

Equinox brings ‘henge’ effect to cities laid out on a grid The fall equinox, which arrives Tuesday in the U. S., brings shorter days, and chances to witness alignment between Earth and the sun. It's a modern version of ancient observances of a celestial shift. National What the equinox 'henge' effect tells us about U. S. cities September 21, 20263:50 PM ET By  Bill Chappell The sun creates a "Chicagohenge" effect in Chicago, as the sun rises and falls straight down streets such as Kinzie and Madison one or two days each year, as seen here on Sept. 22, 2017. Sasmaz/Anadolu Agency/ hide caption toggle caption Bilgin S. Sasmaz/Anadolu Agency/ The fall equinox brings shorter days, and the change of seasons. S. cities, it's also a chance to witness the striking alignment between the sun and Earth, as sunrises and sunsets align with city streets running east and west. It's a modern version of ancient observances of a celestial shift, like sunrise at Stonehenge. "Humans still connect with how special it feels," says Geoff Boeing, who studies city design as the chair of the Department of Urban Planning and Spatial Analysis at the University of Southern California. "The things we built helped us to frame the universe in a certain way," Boeing adds. In this case, that framing is literal. Take Chicago, for instance. "In Chicago's canyon of tall buildings, especially in the downtown area, the sun will be framed , and the setting sun will be framed ," says Michelle Nichols, senior director of public programs at the Adler Planetarium in Chicago. "The effect itself is accentuated ." Fans of the phenomenon call it "Chicagohenge," after England's famously solar-aligned Stonehenge. It occurs thanks to Chicago's street design that follows the cardinal points of the compass: north, east, west and south. All you need to see it, Nichols says, is a wide street running east and west. A bit of elevation might also help. The 2026 fall equinox arrives on Sept. 22 in the U. S., with the precise time falling in the evening, according to the U. It means roughly equal hours of day and night, as autumn begins in the Northern Hemisphere and spring starts in the Southern Hemisphere. Other cities that are laid out on a grid, such as Washington, D. C. and Phoenix can also offer good chances to spot a "henge" moment. Photographers, tourists and residents gather downtown to view "Chicagohenge" on March 22, 2025, in Chicago.