| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°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 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F | |
| Average First Frost Date: | Sep.11 - Sep. 20 | |
| Average Last Frost Date: | May 21 - May 31 | |
| Koppen-Geiger Climate Zone: | Dsb - Humid Continental Climate - Dry Cool Summer | |
| Ecoregion: | 10m - Okanogan Valley | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 98862 - Winthrop, WA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 14 | 19 | 26 | 32 | 40 | 46 | 50 | 50 | 41 | 32 | 25 | 15 | 32 |
| Avg Max Temp (°F) | 30 | 38 | 50 | 61 | 70 | 77 | 85 | 85 | 76 | 61 | 41 | 29 | 59 |
| Avg Precip (In.) | 1.78 | 1.4 | 1.02 | .73 | 1 | .97 | .7 | .65 | .57 | .8 | 1.81 | 2.32 | 13.74 |