Waterville, Washington has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 2.1 °C (low) to 13.5 °C (high). Annual precipitation averages 293.1 Millimeters. Waterville is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.2 °C | -0.6 °C | 40.13 mm |
| February | -5.8 °C | 2.4 °C | 25.91 mm |
| March | -2.4 °C | 7.8 °C | 27.94 mm |
| April | 1.3 °C | 13.4 °C | 16.76 mm |
| May | 5.6 °C | 18.8 °C | 24.38 mm |
| June | 8.9 °C | 22.7 °C | 25.65 mm |
| July | 12.7 °C | 28.1 °C | 10.92 mm |
| August | 12.3 °C | 28 °C | 9.4 mm |
| September | 8.3 °C | 22.9 °C | 7.11 mm |
| October | 1.8 °C | 14.1 °C | 20.83 mm |
| November | -3.2 °C | 4.6 °C | 32 mm |
| December | -7.2 °C | -0.7 °C | 52.07 mm |
| Annual | 2.1 °C | 13.5 °C | 293.1 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |