Spokane, Washington has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 3.3 °C (low) to 15.6 °C (high). Annual precipitation averages 459 Millimeters. Spokane is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.7 °C | 2.6 °C | 55.12 mm |
| February | -3.2 °C | 5.4 °C | 39.12 mm |
| March | -0.9 °C | 10.3 °C | 50.8 mm |
| April | 2 °C | 14.9 °C | 37.34 mm |
| May | 6.2 °C | 20.3 °C | 42.67 mm |
| June | 9.7 °C | 23.9 °C | 38.1 mm |
| July | 12.4 °C | 30 °C | 12.19 mm |
| August | 11.7 °C | 29.9 °C | 11.18 mm |
| September | 7.4 °C | 24.3 °C | 15.75 mm |
| October | 2.7 °C | 15.8 °C | 33.78 mm |
| November | -0.8 °C | 7.2 °C | 56.9 mm |
| December | -3.6 °C | 2.3 °C | 66.04 mm |
| Annual | 3.3 °C | 15.6 °C | 458.99 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |