CHAMPAIGN - Illinois has recently experienced some of the coldest weather that has been seen in decades and, in some locations, ever.
The National Oceanic and Atmospheric Administration cooperative weather observer at Mt. Carroll in northeastern Illinois reported a temperature of -38 degrees on the morning of Jan. 31. “The temperature in Mt. Carroll may be a new state record, if officially confirmed,” said Brian Kerschner, spokesperson for the Illinois State Climatologist’s Office at the Illinois State Water Survey.
The current record-cold temperature is -36 degrees recorded in Congerville of Woodford County on Jan. 5, 1999. When it appears that a state record temperature may have been broken, a state climate extremes committee reviews the observations to assess its validity. This team typically includes the State Climatologist’s Office, the Midwestern Regional Climate Center, and federal climate experts, such as from the National Weather Service and the National Center for Environmental Information.
Most of Illinois was in the deep freeze during the last two days of the month. With a recording of -31 degrees, Rockford broke their all-time low temperature, which was previously -27 degrees on Jan. 10, 1982, the National Weather Service Forecast Office in Chicago reported.
During the mornings of Jan. 30 and 31, numerous locations in northern Illinois reported temperatures in the -20s and some locations going below -30 degrees. Minimum temperatures were below 0 degrees throughout most of the state, except for the southern regions. Daily mean temperatures were generally 15 to 20 degrees lower than the 30-year average temperature.
Some other notable temperatures included -35 degrees at Elizabeth, -32 at Galena, -30 at Rochelle, -33 at Aledo, -27 at Ottawa (CoCoRaHS), -26 at DeKalb, -22 at Joliet, -21 at Galesburg, -17 in Champaign, and -16 in Decatur.
In the southern counties, Cairo reached 12 degrees and Carbondale and Rosiclare saw 4 degrees.
Numerous schools, businesses, and government offices were closed throughout the state because of the dangerously cold wind chills.
January started out warm and ended with record-breaking cold
After an unseasonably warm start, January brought a torrent of winter storms, and ended with a monumental Arctic air outbreak that shattered many record-cold temperatures across the state.
During the first 10 days of January, the statewide average temperature was 9 to 14 degrees above normal. The highest temperature recorded for the month was 66 degrees, which occurred at two stations, one in Pulaski County on Jan. 2 and another in Jersey County on Jan. 8.
During the last 10 days of the month, average temperatures were 5 to 21 degrees below normal with Northwest Illinois experiencing the most extreme departures from average. With the two weather extremes, the preliminary average statewide temperature in January was 24.7 degrees, which is 1.7 degrees below the long-term average.
Regions near and south of I-70 generally reported departures of 1 to 3 degrees above the long-term average. However, many locations in northern Illinois reported departures of 1 to 3 degrees below the long-term average, while the central portion of the state had near to slightly below average temperatures.
Statewide average precipitation was 3.51 inches, which is 1.44 inches above the long-term average. The highest monthly rainfall total of 6.50 inches occurred at a station near Cobden (Union County), 1.50 inches of which fell in a single day on Jan. 5.
Snow was abundant across the state in January, with all of Illinois recording at least some accumulating snowfall. The highest snowfall totals of 15 to over 20 inches were common in west-central and northwest Illinois. These same regions generally recorded accumulations of 10 to 15 inches above the long-term average.
The highest monthly snowfall total was from Moline (Rock Island County) where 30.2 inches were reported, which is 20.8 inches above normal for January. Rockford (Winnebago County) received 24.9 inches, which is 14.7 inches above the long-term average for the month.
The Climate Prediction Center is forecasting an above-normal chance for a wetter than average February statewide. The highest probabilities are located toward the eastern side of Illinois. Below-average temperatures are favored for much of central and northern Illinois, with no strong signals further south.