Asotin, Washington has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 43.6 °F (low) to 65.7 °F (high). Annual precipitation averages 12.6 Inches. Asotin is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 31.1 °F | 43.1 °F | 1.17 in. |
| February | 31.9 °F | 48.3 °F | 1.25 in. |
| March | 35.9 °F | 56.4 °F | 1.34 in. |
| April | 41.2 °F | 64.2 °F | 1.16 in. |
| May | 47.9 °F | 73.3 °F | 1.43 in. |
| June | 54.0 °F | 80.1 °F | 1.13 in. |
| July | 59.9 °F | 92.1 °F | 0.52 in. |
| August | 59.6 °F | 91.8 °F | 0.46 in. |
| September | 52.5 °F | 81.6 °F | 0.53 in. |
| October | 42.9 °F | 65.4 °F | 1.06 in. |
| November | 35.6 °F | 50.5 °F | 1.38 in. |
| December | 30.4 °F | 41.8 °F | 1.19 in. |
| Annual | 43.6 °F | 65.7 °F | 12.62 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7b : 5°F to 10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |