9:22 a.m. Update
The dense fog advisory has been cancelled.
The National Weather Service says a portion of East Central Illinois is under a dense fog advisory until 9 a.m. Thursday.
The advisory includes Champaign, Coles, Douglas, Edgar, and Vermilion counties.
Visibility could be reduced to one quarter of a mile. So be sure to slow down, use your headlights and leave plenty of distance ahead of you when driving around the area.
Meanwhile, all of East Central Illinois remains under a Flash Flood Watch until Thursday night.