MOUNT CARROLL – The Jan. 31 temperature reading of 38 degrees below zero in this Carroll County village of 1,700 was certified as official last week by the Illinois Climate Extremes Committee.
The new low, resulting from a chilling polar vortex throughout the Sauk Valley that extended into February, is the coldest recorded temperature in state history.
Congerville, a small community near Peoria, had the previous mark of 36 below zero, set in 1999, after besting Mount Carroll’s previous record.
The verifying committee consists of members from the Illinois State Climatologist Office, National Weather Service, and the National Center for Environment Information.
Located along the edge of the Driftless Area, Mount Carroll has one of Illinois’ longest-running weather monitoring stations, which began in 1895 and has been observing temperatures on a regular basis since 1897. It recorded a low of 35 below zero on Jan. 22, 1930, which was the sole state record until it was matched by Elizabeth, 23 miles northwest of Mount Carroll, on Feb. 3, 1996.
Mount Carroll also saw unofficial record daily low temperatures established this year on four other dates from Jan. 26 to Feb. 1, when another reading of 36 below was registered.