| 2023 Hardiness Zone: | Zone 8b: 15°F to 20°F Zone 8a: 10°F to 15°F Zone 7b: 5°F to 10°F |
| 2012 Hardiness Zone: | Zone 8b: 15°F to 20°F Zone 9a: 20°F to 25°F Zone 8a: 10°F to 15°F Zone 7b: 5°F to 10°F |
| 1990 Hardiness Zone: | Zone 8a: 10F to 15F |
| Average First Frost Date: | Sep. 21 - Sep. 30 |
| Average Last Frost Date: | Jun. 21 - Jun. 30 |
| Koppen-Geiger Climate Zone: | Csa - Hot-Summer Mediterranean Climate |
| Ecoregion: | 78b - Oak Savanna Foothills |
| Heat Zone Days: | 61 - 90 days Over 86°F |
Annual Climate Data for ZIP Code 97544 - Williams, OR | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 30 | 31 | 33 | 36 | 40 | 46 | 50 | 51 | 46 | 39 | 34 | 30 | 39 |
| Avg Max Temp (°F) | 46 | 50 | 55 | 61 | 69 | 76 | 85 | 84 | 79 | 68 | 52 | 45 | 64 |
| Avg Precip (In.) | 5.11 | 3.94 | 3.25 | 1.92 | 1.28 | .62 | .36 | .44 | .75 | 1.97 | 4.73 | 5.25 | 29.62 |