| 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 8a: 10F to 15F |
| Average First Frost Date: | Nov. 21 - Nov. 30 |
| Average Last Frost Date: | Mar. 11 - Mar. 20 |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate |
| Ecoregion: | 3c - Prairie Terraces |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 97223 - Portland, OR | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 35 | 36 | 39 | 42 | 47 | 51 | 55 | 55 | 52 | 45 | 39 | 35 | 44 |
| Avg Max Temp (°F) | 46 | 51 | 56 | 61 | 67 | 73 | 80 | 80 | 75 | 64 | 52 | 46 | 63 |
| Avg Precip (In.) | 6.04 | 4.99 | 4.28 | 2.92 | 2.4 | 1.69 | .67 | .92 | 1.76 | 3.17 | 6.38 | 6.65 | 41.87 |