Hiawatha, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.6 °C (low) to 15 °C (high). Annual precipitation averages 984.8 Millimeters. 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 | -11.3 °C | -2 °C | 30.73 mm |
| February | -9.2 °C | 0.5 °C | 35.31 mm |
| March | -3.1 °C | 7.9 °C | 54.36 mm |
| April | 3.1 °C | 16.1 °C | 98.3 mm |
| May | 9.7 °C | 22.1 °C | 121.41 mm |
| June | 15.4 °C | 27.2 °C | 142.24 mm |
| July | 17.3 °C | 28.8 °C | 113.03 mm |
| August | 15.9 °C | 27.9 °C | 111.76 mm |
| September | 11.2 °C | 24.4 °C | 100.33 mm |
| October | 4.6 °C | 17.2 °C | 75.44 mm |
| November | -2.1 °C | 8.3 °C | 58.42 mm |
| December | -7.9 °C | 1 °C | 43.43 mm |
| Annual | 3.6 °C | 15 °C | 984.76 mm |
| 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 : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |