Much of Wisconsin to experience high temperatures, heat indexes above 100 this week

Summer isn’t over yet.

A heatwave is hitting Wisconsin this week, with parts of the state expecting heat indexes above 100 degrees Monday and Tuesday. 

The National Weather Service has issued excessive heat warnings and advisories for much of the state for those two days. Aidan Kuroski, a meteorologist with the National Weather Service’s Sullivan office, said the temperatures are so high because of a ridge or core of warmer air flowing from the south.

“With the good flow that you get from southerly areas, you get a lot of moisture with that too and that moisture — in addition to the hot temperatures — is causing the heat indices to just go through the roof,” Kuroski said. 

The heat index is “what the temperature feels like to the human body when relative humidity is combined with the air temperature,” according to the National Weather Service.

Madison is expecting a high heat index of 105 degrees Monday afternoon and 109 degrees Tuesday afternoon. Green Bay is expecting a high heat index of 101 degrees on Monday afternoon and 96 degrees on Tuesday afternoon. In Milwaukee, the high heat index is expected to be 92 degrees on Monday afternoon and 103 degrees on Tuesday afternoon.

The heat warnings and advisories can be found on the National Weather Service website.

“The risk is certainly more focused towards the west but there is heat risk across much of Southern Wisconsin,” Kuroski said.

Temperatures are expected to go back down starting Wednesday. 

Extreme heat causes the “highest number of annual deaths among all weather-related hazards,” according to the Federal Emergency Management Agency.

The U.S. Centers for Disease Control and Prevention says older adults, very young people and people with “mental illnesses and chronic diseases” are the most at risk during times of extreme heat.

Dr. Sheryl Bedno, the chief medical officer in the bureau of environmental and occupational health with the Wisconsin Department of Health Services, said extreme heat can impact anyone.

“Heat can make people ill or sick — and it can be healthy people or people… who are in the more vulnerable groups,” Bedno said. 

Bedno said people who have heart or respiratory diseases and who may have difficulty breathing should be cautious during heat warnings and advisories, as well as people who work outdoors.

In Milwaukee, there are several cooling sites in public buildings like libraries, senior centers and community centers. Mike Totoraitis, Milwaukee’s commissioner of health, said those are open to anyone who needs to get out of the heat.

“Our counterparts in Milwaukee housing (Milwaukee County Housing Division) are going to be going out and doing outreach and making sure folks have water and leading them to cooling shelters when needed,” Totoraitis said.

A Monday statement from the Wisconsin Public Service Commission said state law prohibits utilities from discontinuing service when heat watches or warnings are in effect. 

“Additionally, a utility is required to make reasonable attempts to reconnect service to an occupied dwelling that has been disconnected for nonpayment when an occupant states that there is a potential threat to health or life that results from the combination of the heat and loss of service,” the statement said.