What is Chicagohenge?

 

Twice each year the sun lines up with Chicago’s city buildings to create a beautiful sight. This alignment is called Chicagohenge and happens each year around the Vernal and Autumnal Equinoxes. People line up on bridges over east-west streets to watch the turn between day and night from deep within the city.

The name “Chicagohenge” is a nod to Stonehenge, a prehistoric rock monument built in England that was designed to line up with the Summer and Winter Solstices.

The best times to see Chicagohenge are the few hours after sunrise which is around 6:45 AM CDT and the hours before sunset which is a little after 7:00 AM CDT. Today and tomorrow will likely be your best days to see it since the second half of the week will be rainy. If you miss it this year, don’t worry - it will return in just 6 months when fall starts.

The start of Spring brings much more than just a pretty sight in Chicago, we’re also going to start seeing some big changes over the next few months.

One change that we saw over the weekend was the switch to having more day than night. Daylight lasts 12 hours and 11 minutes today, but we’re quickly gaining more and more light each day. Just 1 month from now, our days will be nearly 1.5 hours longer.

As we orbit the sun, the tilt of the Earth’s axis becomes more directed toward the sun during the Spring, eventually pointing toward the sun on the Summer Solstice. With the Northern Hemisphere receiving the sun’s rays more directly, the sun appears higher in our sky.

The sun angle 1 month from today will be over 10° higher, resulting in not only longer days, but also warming temperatures. Our current average temperature is still in the upper 40’s, but in a month, it will warm into the lower 60’s.