Keokuk, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43 °F (low) to 62.2 °F (high). Annual precipitation averages 40 Inches. Keokuk is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 17.3 °F | 33.8 °F | 1.68 in. |
| February | 20.8 °F | 38.4 °F | 1.85 in. |
| March | 31.0 °F | 50.6 °F | 2.57 in. |
| April | 41.9 °F | 63.2 °F | 4.05 in. |
| May | 53.3 °F | 73.4 °F | 5.36 in. |
| June | 63.1 °F | 82.5 °F | 5.04 in. |
| July | 66.9 °F | 86.3 °F | 4.21 in. |
| August | 64.7 °F | 84.7 °F | 3.77 in. |
| September | 56.3 °F | 78.2 °F | 3.61 in. |
| October | 44.5 °F | 65.6 °F | 3.26 in. |
| November | 32.9 °F | 51.2 °F | 2.63 in. |
| December | 22.9 °F | 38.7 °F | 1.95 in. |
| Annual | 43 °F | 62.2 °F | 39.98 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |