Based on what we have seen so far in January, Illinois has been warmer and wetter than normal with little snowfall.
The statewide average temperature is 27.9 degrees, 3.9 degrees above normal. The statewide average precipitation (rain plus the water content of snow) is 1.6 inches, 0.4 inches above normal.
Snowfall has been light across Illinois. In fact, the Midwest has been very quiet so far this month with below-normal snowfall everywhere except for MN and the northern half of WI (map below). Northern Illinois, which is normally the snowiest spot in the state, is down 5 to 10 inches for the month so far. It has been a relatively quiet month with few storm systems and the precipitation we have gotten has more likely fallen as rain (or freezing rain) instead of snow. Of course, it’s tough to get snow when you are almost 4 degrees above normal.
The other notable features of January have been the prevalence of thunderstorms, fog, and overcast days. Thunderstorms in January are somewhat rare, but can occur when we have warmer stretches of weather.
So far in January, Chicago O’Hare airport has reported 2 days with thunder, and 14 days with fog. In the 19 full days in January, they had 3 clear days, 6 partly cloudy days, and 10 cloudy days. On average, Chicago sees about 2 days with fog in January and reports of thunder about once every other year.
Other reports of fog for January in Illinois include Rockford with 13 days, Peoria with 14 days, Quincy with 15 days, Champaign with 16 days, Springfield with 15 days, Bloomington with 12 days, and Carbondale with 12 days.