Chicago, Ill. – Wildfire smoke will continue affecting northern Illinois through Friday while hot, humid conditions set the stage for scattered thunderstorms ahead of a weekend cold front that will finally bring cooler air by Sunday.
According to the National Weather Service in Chicago, lingering smoke from Canadian wildfires will remain over the region through Friday before gradually improving. Scattered showers and thunderstorms are expected to develop Friday afternoon and again on Saturday, with the greatest coverage during the afternoon and evening hours. While not everyone will see rain, any storm could produce frequent lightning, gusty winds and locally heavy downpours.
Friday highs will reach 87 to 90 degrees across much of northern Illinois and northwest Indiana, followed by 88 to 91 degrees Saturday. Combined with high humidity, peak heat index values could reach 100 to 105 degrees Saturday afternoon, increasing the risk of heat-related illness for anyone spending extended time outdoors.
A cold front will sweep through Saturday afternoon and evening, pushing storms east before bringing noticeably cooler conditions Sunday. High temperatures will fall into the low to mid-80s, especially near Lake Michigan, offering a break from the heat. Isolated thunderstorms could return Monday, particularly near the Illinois-Wisconsin border.
Residents should limit strenuous outdoor activities during the hottest part of the day, stay hydrated and monitor air quality if sensitive to wildfire smoke. Keep an eye on updated forecasts through Saturday, as the timing and strength of thunderstorms could change and additional advisories may be issued.
