Hiawatha, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38.5 °F (low) to 58.9 °F (high). Annual precipitation averages 38.8 Inches. Hiawatha is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 11.7 °F | 28.4 °F | 1.21 in. |
| February | 15.4 °F | 32.9 °F | 1.39 in. |
| March | 26.5 °F | 46.2 °F | 2.14 in. |
| April | 37.6 °F | 60.9 °F | 3.87 in. |
| May | 49.4 °F | 71.7 °F | 4.78 in. |
| June | 59.8 °F | 80.9 °F | 5.6 in. |
| July | 63.1 °F | 83.9 °F | 4.45 in. |
| August | 60.6 °F | 82.2 °F | 4.4 in. |
| September | 52.1 °F | 76.0 °F | 3.95 in. |
| October | 40.2 °F | 63.0 °F | 2.97 in. |
| November | 28.3 °F | 47.0 °F | 2.3 in. |
| December | 17.8 °F | 33.8 °F | 1.71 in. |
| Annual | 38.5 °F | 58.9 °F | 38.77 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |