| 2023 Hardiness Zone: | Zone 8b: 15°F to 20°F Zone 8a: 10°F to 15°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: | Oct. 11 - Oct. 20 | |
| Average Last Frost Date: | May 1 - May 10 | |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate | |
| Ecoregion: | 3a - Portland/Vancouver Basin | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 97051 - Saint Helens, OR | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 33 | 35 | 38 | 41 | 46 | 50 | 54 | 55 | 51 | 44 | 38 | 34 | 43 |
| Avg Max Temp (°F) | 46 | 51 | 57 | 62 | 69 | 74 | 81 | 81 | 77 | 64 | 52 | 46 | 63 |
| Avg Precip (In.) | 6.15 | 5.31 | 4.62 | 3.55 | 2.71 | 1.95 | .84 | 1.06 | 1.93 | 3.33 | 6.48 | 6.93 | 44.86 |