Madison, Wis. – A sweltering Sunday evening could bring dangerous weather to parts of southern Wisconsin as peak heat index values near 100 degrees ahead of strong thunderstorms between 5 and 9 p.m.
According to the National Weather Service in Milwaukee, a southwest breeze and high humidity will push heat index levels into the upper 90s across cities like Janesville, Dodgeville, and Madison by mid-afternoon. A cold front moving in late Sunday is expected to trigger thunderstorms, with the strongest storms forming north and west of Madison between 5 and 9 p.m. The main hazard will be straight-line winds.
Heat index values will exceed 95°F in cities including Fond du Lac, Kenosha, and Milwaukee from noon to 6 p.m., prompting safety concerns for outdoor events and vulnerable populations. Madison could feel like 97°F by 3 p.m. before storms begin rolling in. The most intense storms are expected near Dodgeville and Baraboo during the evening commute.
Residents are urged to stay hydrated, limit outdoor activity during peak heat, and secure outdoor objects ahead of the storms. If driving during the evening, remain alert for sudden gusts and heavy rain.
Showers and storms should taper off by early Monday morning, with cooler, less humid air returning to the region.
