Waterville, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 2.6 °C (low) to 13.7 °C (high). Annual precipitation averages 966.7 Millimeters. Waterville 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.7 °C | -3.3 °C | 31.24 mm |
| February | -10.8 °C | -0.8 °C | 29.97 mm |
| March | -4.3 °C | 6.3 °C | 50.29 mm |
| April | 2 °C | 14.3 °C | 102.62 mm |
| May | 8.4 °C | 20.8 °C | 124.21 mm |
| June | 14.2 °C | 26.1 °C | 149.1 mm |
| July | 16.4 °C | 28.1 °C | 114.3 mm |
| August | 15.2 °C | 27.1 °C | 107.44 mm |
| September | 10.5 °C | 23.2 °C | 98.04 mm |
| October | 3.8 °C | 15.9 °C | 69.85 mm |
| November | -2.8 °C | 6.9 °C | 51.56 mm |
| December | -8.8 °C | -0.2 °C | 38.1 mm |
| Annual | 2.6 °C | 13.7 °C | 966.72 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 |