Thunderstorms

A thunderstorm is a storm that contains both thunder and lightning. These storms can produce flash flooding, gusty winds, hail, and even tornadoes. The southern part of the United States has the highest number of average annual thunderstorms, especially those states located near the Gulf of Mexico and the Atlantic Ocean.

Thunderstorms occur in Iowa from April through September, with the peak frequency coming in June, ranging from 40 storms per year in the northwest portion of the state to 60 per year in the southeast part.

Source: Penn State University