One of Chicago’s most unique experiences returns this week offering an extraordinary collaboration between the magic of nature and Chicago’s glorious architecture during the autumn equinox.
You’re likely familiar with the prehistoric boulder formation in Wiltshire, England. During the summer and winter solstice, the sun rises behind Stonehenge’s Heel Stone, where its rays are captured within the rock frame, creating a glorious spectacle that thousands of people flock to witness
In Chicago, the equinoxes provide a similar sight right here in our urban metropolis. Dubbed “Chicagohenge“, twice a year for the spring and fall equinoxes the sun lines up directly with Chicago’s streets and beams down the heart of the city splashing through Chicago’s artificial valleys.
This year the autumn Chicagohenge will be best experienced on the official first day of fall which is this coming Saturday, September 23rd.
Remind me what an equinox is again?
The reason we have seasons is due to the fact that the earth is tilted on an axis toward the sun. An equinox happens twice a year when the sun is positioned directly above the equator making day and night approximately equal in length which is why in Latin, equinox means “equal night.”
It is also the time of the year in which the Northern and Southern Hemispheres are distributed equal amounts of light.
Which means a solstice is what?
While both the equinox and solstice are based on the relationship between the sun and the earth, they are not quite the same. The solstice ushers in the summer and winter seasons, and occurs upon the sun’s highest and lowest points in the sky.
As such, the solstice indicates the longest day of the year (June 21 in 2023) and shortest day of the year (December 22 in 2023) with daylight lasting longer during the summer months and shorter in winter months.
What does the autumn equinox mean for Chicago?
The phenomenon of “Chicagohenge” corresponds with the autumn and spring equinoxes. Because Chicago was built on a grid system, that is, with streets arranged at right angles into the shape of a grid, they line up near perfectly on a compass north to south and east to west.
In the week running up to each equinox, the sun, therefore, aligns perfectly with Chicago’s east-west facing streets for both sunrise and sunset meaning it beams down the middle of Chicago’s largest downtown streets to create the “Chicagohenge”.
When can I best experience the autumn Chicagohenge?
In the days before and after the autumn equinox, which will this year take place on Saturday, September 23rd, 2023 at 01:50 am according to the Farmers’ Almanac the sun will align perfectly with Chicago’s east-west facing streets for both sunrise and sunset.
On the day of the autumn equinox itself, the sun will rise in Chicago at approximately 6:38 am and set at 6:46 pm though it can be experienced around these times in the days leading up to and following September 23rd.
Where can I best experience the autumn Chicagohenge?
Park yourself on any east-to-west running street in Chicago just after sunrise or before sunset and you’ll experience the Chicagogenge. Some favorite spotting locations include between Kinzie and Madison as well as E Randolph Street between N State St. and N Michigan Avenue.
For the full Chicagohenge experience, you can capture the phenomenon along Washington Street from Millennium Park.
[Featured image taken by Benjamin Cruz / www.benjamincruzphotography.com]