Kennewick, Washington has a Cold Desert Climate climate (Köppen classification: BWk). Average annual temperatures range from 42.4 °F (low) to 65.7 °F (high). Annual precipitation averages 8.4 Inches. Kennewick is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 28.9 °F | 41.5 °F | 1.22 in. |
| February | 29.9 °F | 47.9 °F | 0.84 in. |
| March | 34.9 °F | 57.7 °F | 0.67 in. |
| April | 40.5 °F | 65.8 °F | 0.68 in. |
| May | 47.8 °F | 75.0 °F | 0.89 in. |
| June | 54.1 °F | 81.8 °F | 0.65 in. |
| July | 59.7 °F | 91.0 °F | 0.22 in. |
| August | 58.8 °F | 89.9 °F | 0.18 in. |
| September | 50.8 °F | 80.2 °F | 0.27 in. |
| October | 41.4 °F | 65.5 °F | 0.69 in. |
| November | 33.8 °F | 50.7 °F | 0.9 in. |
| December | 28.7 °F | 41.0 °F | 1.17 in. |
| Annual | 42.4 °F | 65.7 °F | 8.38 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BWk - Cold Desert Climate |