NORTHERN ILLINOIS — Scattered strong thunderstorms carrying damaging wind and hail are forecast to impact northern Illinois during the late afternoon and evening hours on Monday, May 4, 2026. The National Weather Service Storm Prediction Center issued a severe weather outlook valid through May 5, 2026 at 7:00 AM CDT, with the threat developing along and ahead of an advancing cold front pushing through the region.
Which Areas Are Under Threat Monday
The severe weather outlook covers a wide stretch of northern and central Illinois, placing numerous major cities within the threat zone. Areas including Chicago, Rockford, DeKalb, Aurora, Moline, Galesburg, Peoria, Bloomington, Champaign, Kankakee, Quincy, Springfield, Effingham, East St. Louis, and Mt. Vernon all fall within the outlined risk area on the NOAA Storm Prediction Center map.
The bulk of the threat is concentrated across the northern half of the state where storm coverage is expected to be highest during the late afternoon and early evening window.
What Hazards Are Expected
The two primary hazards associated with Monday’s storm threat are damaging winds and hail. Thunderstorms developing along and ahead of the cold front will carry enough energy to produce wind gusts capable of causing damage, along with hail that could impact vehicles, crops, and property across the affected counties…