Volcano, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 45.8 °F (low) to 71.5 °F (high). Annual precipitation averages 37.9 Inches. 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 | 36.0 °F | 54.2 °F | 6.81 in. |
| February | 37.0 °F | 56.8 °F | 6.48 in. |
| March | 39.0 °F | 61.0 °F | 5.72 in. |
| April | 41.1 °F | 66.0 °F | 3.53 in. |
| May | 46.8 °F | 74.6 °F | 2.2 in. |
| June | 52.7 °F | 84.2 °F | 0.38 in. |
| July | 59.3 °F | 91.9 °F | 0.02 in. |
| August | 58.7 °F | 91.3 °F | 0.09 in. |
| September | 54.9 °F | 86.5 °F | 0.32 in. |
| October | 48.2 °F | 76.0 °F | 1.93 in. |
| November | 39.7 °F | 62.3 °F | 3.7 in. |
| December | 35.7 °F | 52.8 °F | 6.73 in. |
| Annual | 45.8 °F | 71.5 °F | 37.91 in. |
| 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 : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 9a : 20°F to 25°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |