CHICAGO – Thick fog settled over portions of north-central Illinois early Sunday, prompting a Dense Fog Advisory from the National Weather Service in Chicago through 8 a.m.. The advisory covers La Salle, Lee, Grundy, and Kendall Counties, where visibility has dropped below a quarter mile in many rural areas and along key travel routes including Interstate 80 and U.S. 52.
According to forecasters, the fog formed overnight as calm winds and near-freezing temperatures allowed moisture to condense near the surface. In some areas, temperatures dipping below 32°F are producing patchy freezing fog, which may cause slick bridges and overpasses early this morning. Motorists are urged to slow down, use low-beam headlights, and increase following distance until conditions improve after sunrise.
The fog is expected to lift by midmorning as light winds develop and temperatures climb into the upper 40s. Skies will turn mostly sunny this afternoon, ushering in a dry and seasonable day across the Chicago region.
