National Weather Service: Heat advisory possible this week

JANESVILLE — Heat is on the way early in the coming week.

The National Weather Service office in Milwaukee/Sullivan issued a hazardous weather outlook on Friday for excessive heat this week for portions of east central, south central and southeast Wisconsin.

Twenty counties were named in the notice, including Rock, Dane, Jefferson, Walworth, Green, Marquette, Green Lake, Fond du Lac, Sheboygan, Sauk, Columbia, Dodge, Washington, Ozaukee, Iowa, Waukesha, Milwaukee, Layfayette, Racine and Kenosha counties.

Heat index values may reach heat advisory levels on Monday for all of the listed counties and may approach these levels Tuesday in far southeast Wisconsin.

According to the National Weather Service, a heat advisory is issued within 12 hours of the onset of extremely dangerous heat conditions.

“The general rule of thumb for this advisory is when the maximum heat index temperature is expected to be 100 degrees or higher for at least 2 days, and nighttime air temperatures will not drop below 75 degrees,” the weather service said.

“However, these criteria vary across the country, especially for areas that are not used to dangerous heat conditions,” the weather service’s website says.

The forecast in Janesville is for highs in the mid-to-upper 80s Saturday and Sunday, followed by a high of 93 degrees on Monday and a high of 96 degrees on Tuesday. Thunderstorms are in the forecast for Wednesday.

In anticipation of the coming heat, Walworth County said Friday that designated area cooling centers would open this week. The following facilities serve as cooling stations in the county, and are open during their regular business hours:

Andersen LibraryBarrett Memorial LibraryDarien Public LibraryAram Public LibraryEast Troy Lions Public LibraryMatheson Memorial LibraryFontana Public LibraryGenoa City Public LibraryIrvin L. Young Memorial LibraryLake Geneva Public LibraryBrigham Memorial LibraryWalworth Memorial Library