April in Storm Lake is the windiest month of the year. In April, the weather in Storm Lake is typically warm. Average daily high temperature in April is about 15 degrees above zero. On average, Storm Lake has 11 sunny, 10 rainy, 5 cloudy, and 4 partly cloudy days in April. The rains are usually heavy. April as well as January, February, March, and May is considered the most uncomfortable time to visit Storm Lake.