Average Rainfall for Iowa in August

The tables below give monthly averages for rainfall during August at cities, communities and other locations around Iowa.

Each place has a total for the amount of precipitation it usually receives this month. There is also a count of the number of days with wet weather, when precipitation amounts to 0.01 inches (0.25 millimetres) or more.

The rainfall totals are averages based on weather data collected from 1991 to 2020 for the US National Centers for Environmental Information.

You can jump to a separate table for each region of the state: Eastern, Central and Western Iowa.

Eastern Iowa

Average monthly precipitation in August
Days Place Inches Milli­metres
9 Burlington 3.9 98
10 Cedar Rapids 4.4 112
10 Clinton 4.2 107
10 Cresco 4.6 117
13 Davenport 4.0 101
10 Decorah 4.4 112
9 Dubuque 3.8 95
9 Iowa City 4.3 110
8 Keokuk 3.8 96
9 Waterloo 4.2 106

Central Iowa

August averages for total rainfall
Days Place Inches Milli­metres
10 Ames 4.8 121
9 Des Moines 4.2 106
9 Fort Dodge 4.3 108
9 Marshalltown 4.4 111
9 Mason City 3.8 96
9 Ottumwa 4.4 113

Western Iowa

Average amount of rain in August
Days Place Inches Milli­metres
10 Carroll 4.1 103
9 Lake Park 3.5 89
8 Milford 3.5 88
7 Onawa 4.1 103
9 Shenandoah 3.8 96
10 Sioux City 3.9 100
8 Spirit Lake 3.7 94
Reference

NOAA National Centers for Environmental Information (NCEI). Climate Normals.

Iowa Precipitation
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