| Month | High (°F) | Low (°F) | Precipitation (in) |
|---|---|---|---|
| January | 28.1 | 10.9 | 1.0 |
| February | 33.1 | 15.1 | 1.2 |
| March | 46.3 | 26.5 | 2.0 |
| April | 60.1 | 37.2 | 3.7 |
| May | 71.1 | 48.8 | 4.8 |
| June | 80.6 | 59.2 | 5.3 |
| July | 83.9 | 62.9 | 4.2 |
| August | 81.7 | 60.3 | 4.1 |
| September | 75.4 | 51.9 | 3.5 |
| October | 62.3 | 39.6 | 2.7 |
| November | 46.4 | 27.4 | 1.8 |
| December | 33.2 | 16.7 | 1.4 |
| Entire Year | 58.5 | 38.1 | 35.6 |
| City | Average (°F) | Record (°F) | Yearly (inches) | |||
|---|---|---|---|---|---|---|
| High | Low | High | Low | Precipitation | Snow | |
| Burlington | 61.9 | 42.8 | 111 | -27 | 37.4 | n/a |
| Carroll | 59.0 | 37.6 | 112 | -40 | 33.3 | 29.8 |
| Cedar Rapids | 58.6 | 38.6 | 110 | -30 | 35.7 | n/a |
| Des Moines | 60.8 | 41.8 | 108 | -26 | 36.6 | 36.8 |
| Dubuque | 56.6 | 38.3 | 101 | -31 | 38.2 | 42.6 |
| Fort Madison | 61.7 | 44.2 | 107 | -23 | 39.1 | 20.7 |
| Iowa City | 60.5 | 40.3 | 109 | -32 | 34.8 | n/a |
| Iowa Falls | 57.3 | 36.5 | 111 | -34 | 38.1 | 29.4 |
| Lamoni | 61.4 | 41.2 | 113 | -29 | 40.3 | 28.2 |
| Mason City | 56.3 | 35.6 | 107 | -35 | 36.2 | 44.6 |
| Northwood | 54.0 | 34.7 | 107 | -37 | 34.1 | 34.5 |
| Ottumwa | 60.8 | 41.1 | 115 | -36 | 36.9 | n/a |
| Rockwell City | 57.6 | 36.8 | 110 | -35 | 32.0 | 30.8 |
| Sac City | 57.6 | 36.4 | 114 | -35 | 32.9 | 30.5 |
| Sioux City | 60.2 | 37.8 | 108 | -28 | 29.3 | 36.1 |
| Spirit Lake | 56.0 | 37.6 | 109 | -39 | 28.7 | 41.4 |
| Waterloo | 58.3 | 37.5 | 112 | -34 | 36.3 | 39.1 |
| Webster City | 58.2 | 36.2 | 109 | -34 | 36.8 | 33.4 |