| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7b: 5°F to 10°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 Zone 7a: 0°F to 5°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Sep.11 - Sep. 20 |
| Average Last Frost Date: | Jun. 1 - Jun. 10 |
| Koppen-Geiger Climate Zone: | Dsb - Humid Continental Climate - Dry Cool Summer |
| Ecoregion: | 15r - Okanogan-Colville Xeric Valleys and Foothills |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 99040 - Wellpinit, WA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 20 | 25 | 29 | 35 | 42 | 48 | 52 | 52 | 44 | 35 | 28 | 22 | 36 |
| Avg Max Temp (°F) | 33 | 40 | 49 | 59 | 68 | 75 | 84 | 85 | 74 | 59 | 42 | 33 | 58 |
| Avg Precip (In.) | 1.85 | 1.83 | 1.83 | 1.55 | 1.91 | 1.46 | .96 | .76 | .83 | 1.22 | 2.73 | 2.86 | 19.79 |