Soap Lake, Washington has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 39.6 °F (low) to 62.9 °F (high). Annual precipitation averages 7.9 Inches. Soap 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 | 24.2 °F | 36.4 °F | 1.01 in. |
| February | 27.0 °F | 43.8 °F | 0.72 in. |
| March | 31.8 °F | 54.2 °F | 0.74 in. |
| April | 37.6 °F | 63.6 °F | 0.6 in. |
| May | 46.1 °F | 73.4 °F | 0.61 in. |
| June | 52.3 °F | 80.3 °F | 0.67 in. |
| July | 58.4 °F | 89.4 °F | 0.28 in. |
| August | 57.2 °F | 88.3 °F | 0.17 in. |
| September | 48.8 °F | 78.8 °F | 0.27 in. |
| October | 38.5 °F | 63.6 °F | 0.67 in. |
| November | 29.7 °F | 47.1 °F | 0.92 in. |
| December | 24.1 °F | 36.3 °F | 1.27 in. |
| Annual | 39.6 °F | 62.9 °F | 7.93 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |