The phenomenon of the setting sun between the two skyscrapers, also known as Chicagohenge, happens twice a year during the spring and autumn equinoxes. The dates might differ slightly every year, so it is important to follow the news. Photographers say that the visual effect happens ±3 days around the equinox dates.
One of the best spots to check out this occurrence is between the Kinzie and Madison streets! If you are not sure about the exact location and time, we recommend following #Chicagohenge on Twitter.