Coralville, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.1 °F (low) to 60.2 °F (high). Annual precipitation averages 37.4 Inches. Coralville is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 13.5 °F | 30.1 °F | 1.19 in. |
| February | 17.1 °F | 34.7 °F | 1.44 in. |
| March | 28.0 °F | 47.8 °F | 2.3 in. |
| April | 39.2 °F | 61.8 °F | 3.81 in. |
| May | 51.1 °F | 72.6 °F | 4.72 in. |
| June | 61.2 °F | 81.7 °F | 5.22 in. |
| July | 64.7 °F | 85.1 °F | 4.32 in. |
| August | 62.1 °F | 83.2 °F | 4.16 in. |
| September | 53.5 °F | 77.3 °F | 3.43 in. |
| October | 41.5 °F | 64.1 °F | 2.97 in. |
| November | 29.6 °F | 48.6 °F | 2.23 in. |
| December | 19.2 °F | 35.3 °F | 1.65 in. |
| Annual | 40.1 °F | 60.2 °F | 37.44 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |