A wind chill warning went into effect at midnight and will remain in effect until 11 a.m. Monday.
"This time around it's going to be less wind, but more so the actual temperatures," said ABC7 Eyewitness News meteorologist Phil Schwarz.
People waiting outside for public transportation Sunday night were dealing with cold weather but expected it would be much worse in the morning.
The good news is that if you are along the lakefront, it only went down to about zero degrees overnight, but the suburbs are another story.
"I'm done with it," said Autumn Starr. "I really want it to be over."
"We have sad lamps for seasonal affective disorder and stuff like that. I don't know, it's really draining emotionally," Andrea Mitchell said.
The brutal cold is especially wearing on those who rely on public transportation. Hoping to provide added shelter to commuters, the Union Pacific Railroad Metra line has kept all its stations open around the clock this weekend, even outside regular agent hours.
Meanwhile, CTA users are finding ways to minimize time spent standing in the cold waiting for the next train or bus.
"I use the internet. I use my phone. And I know what time the bus is supposed to be here. It's a little off sometimes," said CTA rider Kevin Hill.
"I do this six days a week. Travel to Loyola and back. So, it's been kind of rough for me," CTA rider Knutha Weekley said.
But while the streets were mostly empty Sunday night, the cold temps didn't seem to bother the folks at Millennium Park's ice rink.
"My boyfriend and I are on a staycation, so we're staying downtown," said Jessica Anderson. "But he's from Florida, and he can't ice skate. So, he gave it a good try, but he's sitting on a bench."
Then, there was a group of college students in from Puerto Rico for the week.
"It's overwhelming," said Christopher Sang. "I have no idea. I'm freezing right now, so we'll see how it goes."