Average Annual Precipitation for Iowa
The tables below give yearly averages for rainfall plus snowfall at cities, towns and lakes in Iowa.
Each place has a total for the amount of precipitation it usually receives in a year. Most locations also have information on the number of days with wet weather. That includes the days when precipitation amounts to 0.01 inches (0.25 millimetres) or more.
The annual precipitation totals are averages based on weather data collected from 1981 to 2010 for the NOAA National Climatic Data Center.
You can jump to a separate table for each region of the state: Eastern, Central and Western Iowa.
Eastern Iowa
| Days | Place | Inches | Millimetres |
|---|---|---|---|
| 114 | Burlington | 38.5 | 977 |
| 121 | Cedar Rapids | 37.6 | 955 |
| 117 | Clinton | 34.6 | 879 |
| 110 | Cresco | 36.4 | 925 |
| – | Davenport | 36.0 | 915 |
| 109 | Decorah | 34.7 | 881 |
| 115 | Dubuque | 36.3 | 921 |
| 108 | Iowa City | 37.6 | 955 |
| 104 | Keokuk | 39.2 | 996 |
| 112 | Waterloo | 34.6 | 878 |
Central Iowa
| Days | Place | Inches | Millimetres |
|---|---|---|---|
| 102 | Ames | 35.8 | 910 |
| 113 | Des Moines | 36.0 | 915 |
| 101 | Fort Dodge | 35.6 | 905 |
| 100 | Marshalltown | 37.4 | 949 |
| 112 | Mason City | 35.2 | 894 |
| 112 | Ottumwa | 37.1 | 942 |
| 108 | Rathbun Lake Dam | 38.9 | 988 |
Western Iowa
| Days | Place | Inches | Millimetres |
|---|---|---|---|
| 100 | Carroll | 34.3 | 871 |
| 92 | Lake Park | 30.4 | 773 |
| 89 | Milford | 29.6 | 752 |
| 80 | Onawa | 30.5 | 775 |
| 95 | Shenandoah | 36.3 | 923 |
| 101 | Sioux City | 27.7 | 705 |
| 86 | Storm Lake | 34.7 | 881 |
Reference
National Climatic Data Center. NOAA's 1981-2010 Climate Normals.