National Weather Service Weather Forecast Office

A Hot and Humid Day Observed

Across Southern Wisconsin Friday

A low pressure system passing to the northwest during the day produced southerly to southwesterly flow over the state. This southerly flow ushered in very warm and moist air, leading to heat indices above 100 degrees over portions of south central Wisconsin. Morning cloud cover and ouflow from the convection over the lake helped keep the Lake Michigan lakeshore counties in a more bearable state, with temperatures only reaching into the upper 80s and heat indices around 90 degrees. It was the combination of temperatures in the 90s and dew point temperatures reaching into the 70s that produced the hot heat indices in the counties away from the lake, especially in portions of south central Wisconsin. Listed below are some of the sites in southern Wisconsin that reached a heat index of at least 100 degrees.