Here's why:

* Earth's Tilt: The Earth is tilted on its axis. This tilt causes different parts of the Earth to receive varying amounts of sunlight throughout the year.

* Latitude: Chicago is located at approximately 42° North latitude. This means it's relatively far from the equator, which receives direct sunlight twice a year during the equinoxes.

* Tropic of Cancer: The area where the sun can be directly overhead is limited to the region between the Tropic of Cancer (23.5° North) and the Tropic of Capricorn (23.5° South).

Therefore, the sun never reaches a point directly overhead in Chicago.