Dangerous wind chills -20 to -35-degrees expected across the Chicago area from Sunday evening through New Years Day and overnight into Tuesday morning
The Chicago National Weather Service has issued a combination of Wind Chill Warnings and Advisories across the entire Chicago area from 9PM CST Sunday evening until noon CST Tuesday calling for dangerous wind chills -20 to -35-degrees. Coldest readings will likely occur in far west and far southern counties Sunday evening through noon Monday (grey-shaded area on the highlighted map). Under these conditions frostbite can develop on exposed skin in less than 30 minutes, so individuals planning on outdoor activities or caught in the outdoors during this time will need warm clothing and protection for their hands and face.
An upper-level low pressure disturbance forecast to move southeast out of the Canadian provinces of Manitoba and Saskatchewan, preceded and accompanied by a band of cloudiness and light snow will pass over our area Sunday, followed by a reinforcing surge of Arctic-source frigid air that will combine with northwest winds to give the extremely cold wind chills Sunday night into Monday. The very cold air will hold over the Great Lakes and Midwest through Tuesday with a continuation of Wind Chill Advisories here.
Note on the map below Wind Chill Warnings and Advisories (grey and light-blue shaded areas) extend from the Canadian border all the way south into Oklahoma, Arkansas, Mississippi and Alabama.