Deer Park, Washington has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 34.2 °F (low) to 58.4 °F (high). Annual precipitation averages 22.5 Inches. Deer Park is located in USDA Plant Hardiness Zone 6a. 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 | 21.9 °F | 34.3 °F | 3.13 in. |
| February | 22.7 °F | 39.8 °F | 1.73 in. |
| March | 27.4 °F | 49.0 °F | 2.12 in. |
| April | 32.3 °F | 57.4 °F | 1.63 in. |
| May | 39.8 °F | 67.4 °F | 2.04 in. |
| June | 45.3 °F | 73.8 °F | 1.94 in. |
| July | 49.4 °F | 84.5 °F | 0.6 in. |
| August | 48.3 °F | 85.0 °F | 0.58 in. |
| September | 41.2 °F | 74.6 °F | 0.77 in. |
| October | 33.0 °F | 58.7 °F | 1.82 in. |
| November | 27.4 °F | 42.8 °F | 2.85 in. |
| December | 22.0 °F | 33.7 °F | 3.32 in. |
| Annual | 34.2 °F | 58.4 °F | 22.53 in. |
| 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 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |