| 2023 Hardiness Zone: | Zone 9b: 25°F to 30°F |
| 2012 Hardiness Zone: | Zone 9a: 20°F to 25°F Zone 9b: 25°F to 30°F Zone 10a: 30°F to 35°F |
| 1990 Hardiness Zone: | Zone 10a: 30F to 35F |
| Average First Frost Date: | Dec. 21 - Dec. 31 |
| Average Last Frost Date: | Feb. 21 - Feb. 29 |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate |
| Ecoregion: | |
| Heat Zone Days: | 8 - 14 days Over 86°F |
Annual Climate Data for ZIP Code 95521 - Arcata, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 40 | 41 | 42 | 43 | 47 | 50 | 52 | 53 | 50 | 47 | 43 | 40 | 45 |
| Avg Max Temp (°F) | 55 | 56 | 57 | 59 | 61 | 64 | 66 | 67 | 67 | 63 | 58 | 55 | 61 |
| Avg Precip (In.) | 7.96 | 6.19 | 6.45 | 3.58 | 1.83 | .74 | .17 | .42 | .93 | 2.61 | 6.91 | 7.82 | 45.61 |