Granger, Washington has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 3.6 °C (low) to 17.7 °C (high). Annual precipitation averages 196.4 Millimeters. 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 | -3.5 °C | 4.2 °C | 24.89 mm |
| February | -2.7 °C | 8.4 °C | 19.05 mm |
| March | -0.1 °C | 13.6 °C | 15.75 mm |
| April | 2.6 °C | 17.8 °C | 13.46 mm |
| May | 6.8 °C | 22.9 °C | 20.07 mm |
| June | 10 °C | 26.4 °C | 18.03 mm |
| July | 12.8 °C | 31.4 °C | 6.86 mm |
| August | 12.1 °C | 30.8 °C | 5.59 mm |
| September | 7.9 °C | 25.9 °C | 4.32 mm |
| October | 2.9 °C | 18.1 °C | 17.53 mm |
| November | -1.3 °C | 9.7 °C | 24.64 mm |
| December | -3.9 °C | 3.6 °C | 26.16 mm |
| Annual | 3.6 °C | 17.7 °C | 196.35 mm |
| 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 : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |