Granger, Washington has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 38.6 °F (low) to 63.9 °F (high). Annual precipitation averages 7.7 Inches. Granger is located in USDA Plant Hardiness Zone 7a. 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 | 25.7 °F | 39.5 °F | 0.98 in. |
| February | 27.1 °F | 47.1 °F | 0.75 in. |
| March | 31.9 °F | 56.5 °F | 0.62 in. |
| April | 36.7 °F | 64.1 °F | 0.53 in. |
| May | 44.3 °F | 73.3 °F | 0.79 in. |
| June | 50.0 °F | 79.5 °F | 0.71 in. |
| July | 55.1 °F | 88.6 °F | 0.27 in. |
| August | 53.7 °F | 87.4 °F | 0.22 in. |
| September | 46.2 °F | 78.7 °F | 0.17 in. |
| October | 37.3 °F | 64.5 °F | 0.69 in. |
| November | 29.6 °F | 49.4 °F | 0.97 in. |
| December | 25.0 °F | 38.5 °F | 1.03 in. |
| Annual | 38.6 °F | 63.9 °F | 7.73 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |