Chicago temps are nothing like the town in which I grew up in northern Wisconsin. I remember many days of -20F or worse where I grew up. During my senior year in high school, we had a day when it got down to -48F and -90 with the wind chill. We still had school because the buses started. I didn’t go because my car wouldn’t start. The next day it warmed up to a high of -15, but my car still wouldn’t start. lol, the perks of being an upperclassman.
Chicago is comparatively warm. Still colder than Boston, but not nearly as cold as northern Wisc, northern Minnesota or North Dakota.
However, if you are close to Lake Michigan, 20F all of a sudden is bitterly uncomfortable because the wind chill factor is now well below 0. Wet hair freezes nearly instantly, whatever is in your nose freezes, etc. – it can be uncomfortably cold. But it will toughen you up, living in a place that can freeze your ears within 5-10 minutes of exposure. hehe