| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | May 1 - May 10 |
| Koppen-Geiger Climate Zone: | Dsb - Humid Continental Climate - Dry Cool Summer |
| Ecoregion: | 15s - Spokane Valley Outwash Plains |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 99203 - Spokane, WA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 23 | 27 | 31 | 36 | 43 | 50 | 55 | 54 | 46 | 37 | 30 | 25 | 38 |
| Avg Max Temp (°F) | 34 | 41 | 50 | 59 | 67 | 75 | 84 | 84 | 74 | 60 | 43 | 35 | 59 |
| Avg Precip (In.) | 1.75 | 1.54 | 1.74 | 1.34 | 1.77 | 1.26 | .91 | .68 | .85 | 1.16 | 2.45 | 2.31 | 17.77 |