| 2023 Hardiness Zone: | Zone 8b: 15°F to 20°F Zone 9a: 20°F to 25°F |
| 2012 Hardiness Zone: | Zone 8b: 15°F to 20°F Zone 8a: 10°F to 15°F |
| 1990 Hardiness Zone: | Zone 8a: 10F to 15F |
| Average First Frost Date: | Nov. 1 - Nov. 10 |
| Average Last Frost Date: | Apr. 1 - Apr. 10 |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate |
| Ecoregion: | 3b - Willamette River and Tributaries Gallery Forest |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 97446 - Harrisburg, OR | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 33 | 34 | 37 | 39 | 43 | 48 | 51 | 51 | 47 | 41 | 38 | 33 | 41 |
| Avg Max Temp (°F) | 47 | 51 | 56 | 61 | 68 | 73 | 82 | 83 | 78 | 65 | 52 | 46 | 64 |
| Avg Precip (In.) | 7.21 | 5.59 | 4.41 | 2.32 | 2.39 | 1.62 | .35 | .59 | 1.13 | 4.99 | 5.28 | 6.89 | 42.76 |