Moses Lake, Washington has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 3.9 °C (low) to 17.1 °C (high). Annual precipitation averages 213.6 Millimeters. Moses Lake is located in USDA Plant Hardiness Zone 7a. 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 | -4.3 °C | 2.8 °C | 33.53 mm |
| February | -2.9 °C | 6.8 °C | 22.1 mm |
| March | -0.2 °C | 12.6 °C | 19.3 mm |
| April | 2.8 °C | 17.3 °C | 14.73 mm |
| May | 7.3 °C | 22.6 °C | 17.02 mm |
| June | 10.8 °C | 26.2 °C | 17.78 mm |
| July | 13.8 °C | 31.4 °C | 6.86 mm |
| August | 13.2 °C | 31.1 °C | 4.32 mm |
| September | 8.6 °C | 25.7 °C | 5.84 mm |
| October | 3.2 °C | 17.4 °C | 19.56 mm |
| November | -1.3 °C | 8.6 °C | 22.61 mm |
| December | -4.3 °C | 2.6 °C | 29.97 mm |
| Annual | 3.9 °C | 17.1 °C | 213.62 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 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |