Jan 10 | Climate Review and Weather Forecast

The first full week of the year was more winter-like than pretty much anything we had in 2024. Average temperatures this week ranged from the low teens in northern Illinois to the mid-20s in southern Illinois, between 3 and 6 degrees below normal. High temperatures regularly struggled to make it above freezing while low temperatures dipped near to below zero on a few nights. Some of the more impressive nighttime low temperatures included -2 degrees in Champaign and -1 in Lincoln.

A strong winter storm system moved through the state on Sunday and Monday, bringing significant winter precipitation and strong winds. Most of the state north of Interstate 64 had precipitation in the form of snow, with totals ranging from less than a quarter of an inch in far northern Illinois to over 13 inches in Jersey and Calhoun Counties, north of St. Louis. In fact, much of the state between Interstates 64 and 72 saw between 5 and 10 inches of snow over a 48 hour period. The 13 inches received in Jerseyville was the highest single day snowfall total on record there, going back to 1940. Unfortunately, our friends to the south of Interstate 64 were treated to significant ice accumulation, which caused widespread tree damage and power outages. Many folks in the Carbondale and Marion areas were without power for 2 to 3 days. Total precipitation values last week ranged from less than a tenth of an inch in northern Illinois to nearly 2 inches of liquid equivalent in parts of Jackson and Union Counties.

Another winter system is making its way across the southern US Friday and into this weekend. The good news is that because the low pressure center is so much farther south than last week’s system, the cold air will force most precipitation to be in snow form, limiting ice accumulation in Illinois. The maybe less good news is that new snowfall accumulation on the order of 2 to 5 inches is expected for the southern two thirds of the state, with higher end totals possibly reaching 6 to 7 inches in southern Illinois. Temperatures are expected to moderate a bit this weekend, with highs in the upper 20s to mid 30s. That said, all outlooks through the end of January still show best chances for below normal temperatures, so it looks like a very January-like first month of year is in store for us. Wetter than normal conditions are also expected through the next 2-3 weeks as the winter storm track remains active in the eastern U.S. Those lamenting weak winters of the past few years can rejoice. Others who are Florida-dreaming can enjoy some good football this weekend.