Chicago, IL – Northern Illinois is preparing for an active stretch of winter weather from December 18–24, with NOAA’s long-range outlook showing a collision of below-normal temperatures in the far north and above-normal precipitation across much of the state. This combination creates a strong setup for snow, lake-effect activity, freezing rain, and mixed precipitation, especially as Christmas travel intensifies.
According to NOAA, far northern Illinois—including Rockford, Waukegan, Woodstock, and the Wisconsin state line—sits closest to the below-normal temperature zone. This region is most likely to see accumulating snow, with additional lake-effect snow showers possible along Lake Michigan from December 20–23. Some bursts may reduce visibility along I-94 and U.S. 41.
Central portions of northern Illinois—including Chicago, Schaumburg, Naperville, Joliet, and Elgin—sit in a transitional temperature band where freezing rain becomes a concern. From December 19–21, surface temperatures may hover near freezing while warmer air moves overhead, increasing the potential for light glazing, especially overnight and early mornings.
Southern portions of the northern region—including Kankakee, Morris, and Ottawa—lean slightly warmer but will still see a rain–snow mix at times. Late-period cooling from December 22–24 may transition any lingering rain to wet snow as Christmas Eve approaches.
Major travel routes—including I-90, I-94, I-55, I-88, and I-80—may experience slick roads, icy bridges, and reduced visibility, especially from December 21 through Christmas Eve, when impacts appear strongest.
