The city had more than 3,700 beds available for those who need a place to stay overnight, Smith said.
The Illinois Tollway planned round-the-clock patrols until at least Thursday to help stranded motorists, and had assisted 180 motorists between Saturday and Tuesday, officials said.
In Bloomington, where the National Weather Service says the temperature bottomed out at 2 degrees just before dawn Tuesday, the weather was harder on the people than the animals at the Miller Park Zoo, zoo superintendent Jay Tetzloff said.
Some animals that stay outside in the winter, such as the sea lion and otters, get extra food since their bodies are working harder to stay warm, he said. Others, such as birds from warmer climates, have permanent, warmed indoor homes. The staff isn't so lucky.
"Some locks might freeze over, so you're always thawing out locks," Tetzloff said. "You might have to break ice on a water bowl."
National Weather Service meteorologist Matt Friedlein said temperatures will climb to the lower or mid-20s on Wednesday and Thursday, considerably higher than earlier in the week but still below normal for this time of year.
Associated Press writer David Mercer contributed to this report from Champaign.