| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F 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 Zone 5a: -20°F to -15°F Zone 7a: 0°F to 5°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F |
| Average First Frost Date: | Sep.11 - Sep. 20 |
| Average Last Frost Date: | Jun. 1 - Jun. 10 |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate |
| Ecoregion: | 10m - Okanogan Valley |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 98855 - Tonasket, WA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 18 | 24 | 30 | 37 | 45 | 51 | 57 | 56 | 47 | 36 | 29 | 21 | 38 |
| Avg Max Temp (°F) | 31 | 39 | 51 | 62 | 70 | 77 | 84 | 84 | 75 | 60 | 42 | 32 | 59 |
| Avg Precip (In.) | 1.25 | 1.13 | 1 | .99 | 1.08 | 1.22 | .74 | .61 | .54 | .78 | 1.28 | 1.67 | 12.3 |