What is the lowest temperature ever recorded in the Chicago area?
Kyle van der Meer
The Chicago area’s lowest temperatures cluster in the upper 20s or lower 30s below zero range. Chicago’s all-time official record low is minus 27 reached at O’Hare on January 20, 1985. Rockford recorded its all-time record low earlier this year on January 31 when the mercury plunged to minus 31. That same morning the Aurora Airport in Sugar Grove fell to minus 32 while Mt. Carroll in the northwest part of the state established a new record low for Illinois with a reading of 38 below zero breaking the old record of 36 below at Congerville on January 5, 1999. Episodes of extreme cold occur across northern Illinois when a portion of the Polar Vortex, a large circulation of low pressure and extreme cold, descends south into the upper Great Lakes.