| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F Zone 5b: -15°F to -10°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. 21 - Jun. 30 |
| 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 98844 - Oroville, WA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 23 | 26 | 33 | 39 | 47 | 54 | 59 | 58 | 50 | 39 | 32 | 25 | 40 |
| Avg Max Temp (°F) | 32 | 40 | 53 | 63 | 71 | 78 | 85 | 84 | 74 | 60 | 43 | 34 | 60 |
| Avg Precip (In.) | 1 | .81 | .97 | .78 | 1.19 | 1.27 | .9 | .81 | .55 | .71 | .94 | 1.22 | 11.15 |