The preliminary statewide average January temperature was 22.3 degrees, 4.4 degrees below the 1991-2020 average and tied for the 34th coldest on record going back to 1895. The preliminary statewide average total January precipitation was 1.25 inches, 1.06 inches below the 1991-2020 average and tied for the 32nd driest on record statewide.
Data are provisional and may change slightly over time.
Is this what winter used to be?
All four of Illinois’ distinct seasons are getting warmer thanks to human-caused climate change; however, winter is warming far faster than the other seasons. As a result, we have experienced many more mild winters in recent decades; and this trend made last month’s persistently cold weather seem particularly extreme. Daily temperatures and departures from normal in Quincy show much of the first and third weeks of the month had temperatures that were consistently 5 to 30 degrees below normal (Figure 1).
January average temperatures ranged from the high teens in northwest Illinois to the low 30s in southern Illinois, between 2 and 8 degrees below normal. Persistent snowpack in southern Illinois helped depress temperatures farther below normal than in relatively snow-less northern Illinois (Figure 2). The warmest point in the state last month was Du Quoin at 31.7 degrees, and the coldest point in the state was Stockton at 16.9 degrees. The few warm spells in January broke 10 daily high maximum temperature records. The extreme cold in the middle of the month broke 23 daily low maximum temperature records and 15 daily low minimum temperature records, including -20 degrees in Springfield.
Overall, the preliminary statewide average January temperature was 22.3 degrees, 4.4 degrees below the 1991-2020 average and tied for the 34th coldest on record going back to 1895.
Snowy Southern Illinois
Depending on who you talk to, January 2025 was either a very active winter weather month or quite a boring one. An active storm track setup across the southern half of the state in the first week of January, pushing multiple winter storms through the state, which produced multiple rounds of heavy snow mostly along and south of Interstate 70. The result was a strong gradient of snowfall opposite of what is typical for this time of the year, with more in southern Illinois than northern Illinois.
January total snowfall ranged from over 12 inches in south-central Illinois to less than 1 inch in northwest Illinois. Much of the southern half of the state had 1 to 8 inches more snowfall than normal in January, while northern Illinois racked up a 1-to-8-inch snowfall deficit (Figure 3). Last month was the fifth snowiest January on record in Fairfield with 15.6 inches and the snowiest since 1996. Meanwhile, Moline had only 2.3 inches of snow in January, the lowest amount since 2018 and fourth lowest there since 1989.
Other than a couple of noteworthy snow and ice events, January was otherwise mostly dry across Illinois. Total January precipitation ranged from just over 5 inches in far southern Illinois to less than a quarter of an inch in far northwest Illinois. Most of northern and central parts of the state were around 1 to 2 inches drier than normal last month and only the southern seven counties were wetter than normal (Figure 4).
Overall, the preliminary statewide average total January precipitation was 1.25 inches, 1.06 inches below the 1991-2020 average and tied for the 32nd driest on record statewide.
Outlooks
The Climate Prediction Center outlooks, reflecting model tendencies and expert assessments, continue to lean into La Niña influence on our late winter and early spring weather across the U.S. Here in Illinois, the expectation is for near normal temperatures and above normal precipitation for both the last winter month of February and the first two months of spring (Figure 5).
