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
| 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
| 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
| 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.