Average Temperatures for Iowa in September

Average temperatures for September at cities, towns and other locations around Iowa are listed below in degrees Fahrenheit and Celsius.

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

The tables give the normals for maximum and minimum temperatures based on weather data collected from 1991 to 2020 by the US National Centers for Environmental Information.

Eastern Iowa

Average September temperatures
High °F Low °F Place High °C Low °C
77 55 Burlington 25 13
77 53 Cedar Rapids 25 12
76 55 Clinton 24 13
74 48 Cresco 23 9
76 53 Davenport 25 12
76 52 Decorah 25 11
75 54 Dubuque 24 12
76 52 Iowa City 25 11
77 56 Keokuk 25 14
77 52 Waterloo 25 11

Central Iowa

Average daily temperatures in September
High °F Low °F Place High °C Low °C
77 54 Ames 25 12
77 55 Des Moines 25 13
74 51 Fort Dodge 23 10
75 51 Marshalltown 24 10
74 49 Mason City 23 9
77 53 Ottumwa 25 12
77 54 Rathbun Lake Dam 25 12

Western Iowa

September temperatures: daily averages
High °F Low °F Place High °C Low °C
76 52 Carroll 25 11
76 51 Lake Park 24 11
74 52 Milford 23 11
78 50 Onawa 26 10
79 55 Shenandoah 26 13
77 51 Sioux City 25 11
73 52 Spirit Lake 23 11
74 53 Storm Lake 23 11
Reference

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

Iowa Temperatures
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