Polar air that swept into the area over the weekend delivered the lowest temperatures observed so far this season.
Sunday marked a 4th straight day to post a temperature deficit, making it the longest stretch of sub-normal readings this winter. Clouds and flurries off lake Michigan kept readings in the 20s most areas Sunday night, and sunshine Monday afternoon allowed city temps to peak near freezing.
As a result, official readings at O’Hare airport averaged just above normal for the day. More widespread and sustained moderation in temperature is expected Tuesday night and Wednesday as southwest winds lock in. Daytime highs are expected to reach the mid and upper 30s.
The greater anomaly will be with nighttime readings. Mild air and extensive cloud cover will keep daily low temps close to the normal high for mid to late January.
Cloudy skies may also bring wet snow Thursday and Friday.