Green Bluff, Washington has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 37 °F (low) to 57.8 °F (high). Annual precipitation averages 23.9 Inches. Green Bluff is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 24.0 °F | 34.8 °F | 2.9 in. |
| February | 25.0 °F | 39.6 °F | 2.05 in. |
| March | 29.6 °F | 48.2 °F | 2.49 in. |
| April | 34.7 °F | 56.5 °F | 1.98 in. |
| May | 42.3 °F | 66.2 °F | 2.02 in. |
| June | 47.9 °F | 72.5 °F | 2.05 in. |
| July | 53.5 °F | 83.3 °F | 0.61 in. |
| August | 53.0 °F | 83.6 °F | 0.64 in. |
| September | 45.3 °F | 73.5 °F | 0.87 in. |
| October | 36.0 °F | 58.0 °F | 1.94 in. |
| November | 29.1 °F | 42.9 °F | 2.96 in. |
| December | 23.7 °F | 33.9 °F | 3.35 in. |
| Annual | 37 °F | 57.8 °F | 23.86 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |