Volcano, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 7.7 °C (low) to 21.9 °C (high). Annual precipitation averages 962.9 Millimeters. Volcano is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Dec. 11 - Dec. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.2 °C | 12.3 °C | 172.97 mm |
| February | 2.8 °C | 13.8 °C | 164.59 mm |
| March | 3.9 °C | 16.1 °C | 145.29 mm |
| April | 5.1 °C | 18.9 °C | 89.66 mm |
| May | 8.2 °C | 23.7 °C | 55.88 mm |
| June | 11.5 °C | 29 °C | 9.65 mm |
| July | 15.2 °C | 33.3 °C | 0.51 mm |
| August | 14.8 °C | 32.9 °C | 2.29 mm |
| September | 12.7 °C | 30.3 °C | 8.13 mm |
| October | 9 °C | 24.4 °C | 49.02 mm |
| November | 4.3 °C | 16.8 °C | 93.98 mm |
| December | 2.1 °C | 11.6 °C | 170.94 mm |
| Annual | 7.7 °C | 21.9 °C | 962.91 mm |
| Average First Frost Date | Dec. 11 - Dec. 20 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |