| 2023 Hardiness Zone: | Zone 10b: 35°F to 40°F Zone 9a: 20°F to 25°F Zone 10a: 30°F to 35°F 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 9b: 25F to 30F |
| Average First Frost Date: | Dec. 21 - Dec. 31 |
| Average Last Frost Date: | Mar. 1 - Mar. 10 |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate |
| Ecoregion: | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 95558 - Petrolia, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 40 | 41 | 41 | 42 | 45 | 51 | 54 | 54 | 53 | 48 | 43 | 40 | 46 |
| Avg Max Temp (°F) | 53 | 55 | 56 | 59 | 63 | 66 | 72 | 72 | 73 | 67 | 57 | 53 | 62 |
| Avg Precip (In.) | 12.21 | 11.27 | 9.53 | 4.49 | 1.79 | .49 | .13 | .43 | 1.04 | 4.25 | 9.49 | 11.31 | 66.43 |