Heat index may hit 115 in southeast Iowa this afternoon

MASON CITY — The entire state is under either a heat advisory or an excessive heat warning as heat indices climb well into the triple digits. 

National Weather Service meteorologist Craig Cogil says this is nothing unusual for late July in Iowa. “No, it’s really not a record heat for us. It’s very warm, but we’re not looking at record temperatures around here,” Cogil says. “Most of the records this time of year are well above 100, right around 110 or so. However, our heat index values will be up over 100, and that’s really what’s setting off the heat advisories and the excessive heat warnings that we’re looking at.”

A weather service map depicting the heat indices that are expected for the state today is completely red, magenta and maroon, a sure sign it’s steamy. “The highest appears to be in southeast Iowa, where heat index values of up to 110, maybe even 115, can be expected by this afternoon,” Cogil says. “One thing that might keep the readings a little bit lower, looks like there’s going to be some clouds moving across central Iowa this afternoon, so that may put a little cap on how high the temperatures get.”

The forecast calls for the hot, humid weather to continue into Friday, but then Cogil says, we should get a reprieve.   “Once we get through tomorrow, the cold front moves through the state with a threat of some thunderstorms,” he says. “Then as we head into the weekend, yes, cooler highs, a little bit more like normal into the 80s to maybe lower 90s and less humidity, so overall, not too bad of a weekend.”

These are the hottest days of the year so far, which happen to coincide with the annual bicycle ride across Iowa. Cogil says his wife is making the statewide RAGBRAI trek this year, and he praises her endurance, along with everyone else who’s tackling the challenge.