Forecast: Highs in the 100s possible in weekend heat wave

MASON CITY — The final days of the Iowa State Fair promise to be sweltering, as Iowans are being warned about a late summer heat wave that’s approaching for the weekend.

The past few evenings have felt almost like fall with lows in the 50s and 60s, but National Weather Service meteorologist Cory Martin says daytime high temperatures will be climbing again very soon.

“This weekend and into early next week, we’re looking at highs building into the 90s, potentially, in some spots even into the low one-hundreds,” Martin says. “We’re looking at what you would colloquially refer to as the dog days of summer. We’re looking at just hot afternoon heat index readings pushing into the one-hundreds.”

Many of Iowa’s crops are at critical growth stages and Martin says there’s very little chance for rain, well into next week. “We’re looking at a dry, hot stretch here where the heat builds in and kind of squashes any precip activity that we have in the area,” Martin says. “We’re looking at probably the next week, outside of maybe a few storm chances up in far northern Iowa late this evening to tonight, not much.”

With high temps likely climbing into triple digits this weekend, Martin says it’s certainly possible the weather service will issue heat advisories, or even extreme heat warnings.

“With those, there’s also a time duration component as well, where if we’re expecting the heat to last for several days, that could prompt one of those,” Martin says. “Another contributing factor would be overnight low temperatures. If we’re looking at lows some nights in the mid 70s, that doesn’t provide a whole lot of relief, especially for those that don’t have air conditioning.”

The long-range forecast indicates those high temperatures will last at least as far as next Tuesday, with the prediction of 95 degrees that day in Mason City.