Grays River, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 41.9 °F (low) to 60.5 °F (high). Annual precipitation averages 101.2 Inches. Grays River is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.5 °F | 48.2 °F | 16.15 in. |
| February | 34.6 °F | 51.1 °F | 9.8 in. |
| March | 36.4 °F | 54.2 °F | 11.41 in. |
| April | 38.9 °F | 58.6 °F | 7.82 in. |
| May | 43.9 °F | 64.2 °F | 4.3 in. |
| June | 47.9 °F | 67.6 °F | 3.52 in. |
| July | 51.4 °F | 73.3 °F | 1.09 in. |
| August | 51.5 °F | 74.4 °F | 1.74 in. |
| September | 48.0 °F | 72.0 °F | 3.94 in. |
| October | 42.4 °F | 62.5 °F | 9.72 in. |
| November | 37.7 °F | 52.9 °F | 15.61 in. |
| December | 34.9 °F | 47.5 °F | 16.11 in. |
| Annual | 41.9 °F | 60.5 °F | 101.21 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |