Iowa is likely to see more hot days reaching as high as 106 degrees over the next 30 years, according to a new study that shows a Midwest heat zone projected to dominate the forecast.
The judges extreme heat model created by the First Street Foundationand released Monday, studies the future of climate change in the United States and “identifies the property-level impact of warming and how the frequency, duration, and intensity of extremely hot days will change over the next 30 years under a changing climate.” .
In the study, “extreme heat days” are defined as when the temperature exceeds 125 degrees on a given day. The model predicts that 50 counties next year will experience an extreme heat risk day. But more than 1,000 counties in the United States will experience days over 125 degrees by 2053.
This emerging region, concentrated in a geographic area the foundation calls the “Heat Zone,” stretches from North Texas and Louisiana border Illinois, Indiana, and Wisconsin.
“Rising temperatures are widely discussed as averages, but the focus should be on the expansion of extremes expected in a given year,” said Matthew Eby, founder and CEO of the First Street Foundation. “We must prepare for the inevitable, that a quarter of the country will soon fall into the extreme temperature zone with temperatures exceeding 125°F, and the results will be tragic.”
More: 12 ways Iowans have beaten the heat over the years
The top five metropolitan areas with the most neighborhoods expected to experience these Extreme Danger Days being St. Louis, Kansas City, Memphis, Tulsa and Chicago.
In In Iowa, 63% – or more than 2.4 million homes – have a moderate heat index due to a rising heat index — or “feels like” temperatures. The foundation says a property's heat index indicates a location's relative heat risk, taking into account factors such as heat in the area compared to the rest of the country, as well as how shade, green space and proximity to water affect heat in the property.
The top Iowa counties likely to see the biggest increase in heatwaves over the past 30 years are Fremont, where Sidney is the state seat, in the southwest corner of the state. Lee, home to Fort Madison, in the southeast corner of the state. and neighboring Van Buren, home of Keosauqua.
More: The hottest days in Iowa history
A heat wave consists of three or more consecutive days where the temperature “feels like” meets or exceeds the local definition of a “hot day,” as defined by the institute. “Hot day” temperatures in Iowa range from 98 to 106 degrees.
Although not as serious, 195,342 Polk County Properties are also at risk of Moderate Heat Coefficient.
Related: How to prevent heat deaths from cars as temperatures in Iowa approach 100 degrees
Thirty years ago, the chance of a three-day or longer heat wave in Polk County was 23 percent. Today it is 48% and the foundation predicts that this percentage will increase to 81% in 30 years.
The “hot day” temperature for Polk County is 103 degrees. The county is expected to experience seven hot days this year. The number of days above 103 degrees doubles in 30 years, according to the institute's forecast.
Springfield News-Leader reporter Andrew Sullender contributed to this story.
Virginia Barreda is a rising and general reporter for the Des Moines Register. You can reach her at vbarreda@gannett.com. Follow her on Twitter at @vbarreda2.
