Spokane Valley, Washington has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 3.3 °C (low) to 15.4 °C (high). Annual precipitation averages 471.7 Millimeters. Spokane Valley 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 | 2.6 °C | 56.9 mm |
| February | -3.1 °C | 5.3 °C | 39.62 mm |
| March | -0.8 °C | 10.1 °C | 49.28 mm |
| April | 2.1 °C | 14.6 °C | 37.59 mm |
| May | 6.1 °C | 20 °C | 44.96 mm |
| June | 9.5 °C | 23.6 °C | 38.61 mm |
| July | 12.2 °C | 29.5 °C | 14.73 mm |
| August | 11.7 °C | 29.6 °C | 13.97 mm |
| September | 7.4 °C | 24.1 °C | 14.99 mm |
| October | 2.7 °C | 15.6 °C | 39.12 mm |
| November | -0.8 °C | 7.2 °C | 56.9 mm |
| December | -3.6 °C | 2.3 °C | 65.02 mm |
| Annual | 3.3 °C | 15.4 °C | 471.69 mm |
| 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 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |