Carbondale, Illinois – An increasingly unsettled winter pattern may impact Southern Illinois late next week, with rain and snow chances rising to around 50 percent across the region between Jan 20 and Jan 26. The developing setup points to multiple opportunities for precipitation, with shifting temperatures determining whether rain, snow, or a mix falls at any given time.
According to the National Weather Service and the Climate Prediction Center, Southern Illinois is now included in an area with a 50 percent chance of above-normal precipitation during the 8–14 day period. Temperature signals during that same window suggest near-seasonal variability, placing the region in a transition zone where precipitation type could change quickly as systems move through.
Communities along and south of I-64, including Mount Vernon, Centralia, and Salem, may see rain during milder daytime periods, with snow or a rain-snow mix becoming more likely overnight and during early morning hours. Even modest drops in temperature could allow rain to change to snow on the backside of passing systems.
Farther south, including Carbondale, Marion, and the Interstate 57 corridor, rain appears slightly favored overall. However, colder air filtering in at night could still support brief periods of snow or mixed precipitation, especially if precipitation lingers into the early morning hours.
Repeated rounds of precipitation could lead to slick roads, particularly during commute times along I-57, I-64, Illinois Route 13, and rural highways. Ponding is also possible where rain falls before colder air arrives.
Residents are encouraged to monitor updated outlooks, prepare for changing travel conditions, and allow extra time on the roads. Confidence in timing and impacts will improve as the period approaches, and additional advisories may be issued as individual systems become better defined heading into late January.
