Des Moines Weather in August

The climate in Des Moines during August can be summarized as warm, humid and damp.

August is in the summer in Des Moines and is typically the 2nd warmest month of the year. Daytime maximum temperatures average around a muggy 29°C (84°F), whilst at night 17°C (62°F) is normal.

On average August is the 2nd wettest month of the year in Des Moines with around 105mm 4.1 inches of rain making it a damp time to visit. This rainfall is typically spread over 9 days, although this may vary considerably.

On the flip side this corresponds to an average of 10.3 hours of sunshine per day.

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Des Moines in August 2025.