Milwaukee, Wisconsin – Sweltering heat will push southern Wisconsin into a heat advisory through late Thursday, with heat indices reaching 100°F–105°F across Milwaukee, Madison, and surrounding counties—raising health and infrastructure concerns for nearly 24 hours.
According to the National Weather Service Milwaukee/Sullivan, the heat advisory covers all southern Wisconsin, including Lake Michigan shoreline areas, from midday Wednesday through Thursday evening. Heat indices in southeast and south-central regions may spike above 105°F, especially during the afternoon commute. Milwaukee, Kenosha, Janesville, and Waukesha are among the hardest hit, with feels-like temperatures peaking between 3–6 p.m. Wednesday.
Residents should limit outdoor activity, check on vulnerable neighbors, and never leave children or pets in parked cars. Cooling centers are open across the region, and local officials urge residents to stay hydrated and avoid strenuous work outdoors. The combination of high temperatures and humidity may cause power grid strain and increase the risk of heat-related illness, particularly for those without air conditioning.
While clouds and scattered storms Thursday may bring slight relief, heat indices will remain near 100°F in southeast Wisconsin until showers cool the air by late evening. This stretch marks one of the hottest periods of the summer, with similar extremes last seen in July 2022.
The heat advisory for southern Wisconsin stays in effect through Thursday night. Additional alerts may follow if conditions persist.
