Dec 29 | Weekly Weather Review & Forecast

Average temperatures this past week ranged from the single digits in northwest Illinois to the low 20s in southern Illinois, between 15 and 20 degrees below normal. Actual temperatures regularly dipped below zero across the state, including -15 in Knox and Mercer Counties, -12 in Lee and Cook Counties, and -11 in McLean and Champaign Counties. Combined with 25+ mph sustained winds and 45+ mph wind gusts, wind chill values were in the -25 to -40 degree range. Although the temperatures and wind were not unprecedented for late December, they are fairly rare, occurring only once every 20 to 25 years.  

The wind and temperatures were the headline from last week’s storm, as snowfall totals were modest across the state. Storm total snowfall ranged from 5-6 inches in northwest Illinois to just a trace in far southern Illinois. Most of the state north of I-70 is slightly behind on season to date snowfall, but it’s important to remember February is our snowiest month of the year statewide, so we have a lot of winter to go.

Looking ahead, we see mild and wet weather for the time being. Temperatures will likely reach the mid-50s to low 60s across the state this weekend and into next week, and outlooks for the first full week of January also lean warmer than normal. Meanwhile, 7-day precipitation forecasts are bullish, with forecasted totals over 1 inch aross the state, and pushing 4 inches in far southern Illinois. Despite severe drought currently in the southern tip of the state, heavy precipitation on bare soils can induce some isolated flash flooding. With that said, at least the first inch or two of rain will be greatly beneficial to improving soil moisture conditions in southern Illinois. The week 2 outlook also remains wetter than normal, so enjoy the sun while you can this weekend.