Des Moines, Iowa – Iowa is expected to experience an increasingly active midsummer weather pattern between July 23 and July 27, with above-normal temperatures combining with abundant Gulf moisture to bring periods of heat, humidity and repeated opportunities for showers and thunderstorms. While the heat will build during the day, multiple rounds of rainfall could interrupt outdoor plans and create localized flooding where storms repeatedly develop.
According to the National Oceanic and Atmospheric Administration’s Climate Prediction Center, in its 6-10 Day Outlook issued July 17, Iowa is favored to experience above-normal temperatures during the July 23-27 period. The state is also included in an area favoring above-normal precipitation, increasing the likelihood of more frequent thunderstorm activity than is typical for late July.
In Des Moines, afternoon temperatures are expected to climb above seasonal averages while humidity levels continue to rise. Heat index values will likely make conditions feel even warmer before scattered to numerous thunderstorms develop later in the day. Some storms may produce torrential rainfall, frequent lightning and gusty winds, with localized flooding possible in areas where storms move slowly or repeatedly track over the same locations.
Across eastern Iowa, Cedar Rapids is expected to experience a similar pattern. Warm, humid mornings will give way to increasing instability during the afternoon, creating favorable conditions for thunderstorms capable of producing heavy rainfall and brief travel disruptions. Motorists should be prepared for rapidly changing road conditions during heavier downpours, especially on Interstates 80, 380 and 35.
The hotter and wetter pattern is expected to extend across the Hawkeye State, including Davenport, Iowa City, Waterloo, Sioux City, Ames, Dubuque, Council Bluffs and Mason City. Agricultural areas could benefit from the additional moisture, but repeated heavy rainfall may temporarily slow field work or create standing water in low-lying locations. Storm coverage will vary from day to day, with some communities receiving significantly more rainfall than others.
Although the Climate Prediction Center outlook does not pinpoint the exact timing or location of individual thunderstorms, confidence continues to increase that Iowa will remain in a warmer-than-normal and wetter-than-normal pattern through July 27. Residents should stay hydrated during the afternoon heat, remain alert for rapidly developing thunderstorms, and monitor National Weather Service forecasts for updated severe weather or localized flood advisories as the pattern evolves.
