Chicago was colder this morning than Mars or the North Pole, and winter doesn't technically begin until Wednesday.
Wind chills dropped to 35 degrees below zero in some spots as the area contended with the coldest day of the year so far.
"My legs are burning!" a woman told NBC 5 on her way to the train.
"Unbearably cold," said a dog walker, whose canine clients remained cuddled up inside.
While the National Weather Service recorded temperatures as low as -13 at O'Hare International Airport, Chicago didn't beat the record on this day, previously set at -14.
There's good news ahead, though. NBC 5 weather models show a warm-up on the way. Saturday temperatures are expected to rebound to the mid-30s to 40 degrees in some areas.
How cold did it get near you? Here's a list of low temperatures from the NWS.
Aurora Airport -18
DeKalb Airport -16
Joliet Airport -15
Dupage Airport -15
Rochelle Airport -14
Lewis Airport -14
Morris Airport -14
Lansing Airport -14
O'Hare International Airport -13
Porter County Regional Airport -13
Rockford Airport -13
Kankakee Airport -12
Waukegan Airport -11
Rensselaer Airport -9
Peru Airport -8
Gary Airport -8
Executive Airport -8
Midway Airport -6
Pontiac Airport -5