| 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 |
| 1990 Hardiness Zone: | Zone 8b: 15F to 20F |
| Average First Frost Date: | Nov. 11 - Nov. 20 |
| Average Last Frost Date: | Mar. 21 - Mar. 31 |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate |
| Ecoregion: | 3a - Portland/Vancouver Basin |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 97203 - Portland, OR | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 35 | 37 | 39 | 42 | 47 | 52 | 55 | 56 | 52 | 45 | 40 | 35 | 44 |
| Avg Max Temp (°F) | 46 | 50 | 56 | 60 | 67 | 72 | 79 | 80 | 75 | 64 | 52 | 46 | 62 |
| Avg Precip (In.) | 6.41 | 5.02 | 4.63 | 3.03 | 2.37 | 1.67 | .56 | .86 | 1.71 | 3.61 | 6.34 | 7.21 | 43.42 |