CHICAGO – “Chicagohenge” is set to begin this week as spring is finally upon us.

Chicagohenge is a spectacle that occurs only twice a year over a few days: once around the spring equinox and then again as fall begins.

During the equinoxes, the sunrises and sunsets perfectly align with Chicago streets that run east and west, which allows the sun to rise and set in between the city’s skyscrapers to create a beautiful picture-perfect view.

What is an equinox?

On the vernal equinox in March and the autumnal equinox in September, the equator (0 degrees latitude) is aligned directly with the Sun. Therefore, everywhere on Earth experiences an equal 12 hours of daylight and darkness because the Sun rises due east and sets due west.

HERE’S THE SCIENCE BEHIND THE VERNAL EQUINOX

When is Chicagohenge?

Chicagohenge peaks for three days around this year’s spring equinox:

• Thursday, March 20 – Sunset at 7:03 p.m.
• Friday, March 21 – Sunrise at 6:51 a.m. | Sunset at 7:04 p.m.
• Saturday, March 22 – Sunrise at 6:50 a.m. | Sunset at 7:05 p.m.

Skies look mostly clear Thursday night and Friday morning. Some clouds may ruin the show later Friday but skies clear again for Saturday. 

Where is the best place to see the Chicagohenge?

Any east-west-facing street is a safe bet to catch a glimpse of the spectacle, according to the Adler Planetarium in Chicago. Photographers will be everywhere to get the best shots, so get to a good spot early!

Chicago isn’t the only city with a famed sun show. New York’s “Manhattanhenge” draws massive crowds as well  but its alignment occurs closer to the summer solstice.