Okanogan, Washington has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 39.6 °F (low) to 62.6 °F (high). Annual precipitation averages 12 Inches. Okanogan 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 23.6 °F | 34.2 °F | 1.39 in. |
| February | 25.9 °F | 41.2 °F | 1.02 in. |
| March | 31.8 °F | 53.9 °F | 1.17 in. |
| April | 38.2 °F | 64.3 °F | 0.87 in. |
| May | 45.7 °F | 74.2 °F | 1.16 in. |
| June | 52.1 °F | 80.7 °F | 1.0 in. |
| July | 58.2 °F | 90.2 °F | 0.54 in. |
| August | 57.2 °F | 89.8 °F | 0.31 in. |
| September | 48.6 °F | 80.0 °F | 0.43 in. |
| October | 38.6 °F | 62.9 °F | 0.87 in. |
| November | 30.4 °F | 45.3 °F | 1.42 in. |
| December | 24.8 °F | 35.0 °F | 1.77 in. |
| Annual | 39.6 °F | 62.6 °F | 11.95 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 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 | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |