Etna, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 37.7 °F (low) to 67 °F (high). Annual precipitation averages 22.1 Inches. Etna is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 27.9 °F | 46.0 °F | 4.22 in. |
| February | 29.2 °F | 51.4 °F | 3.12 in. |
| March | 31.3 °F | 56.9 °F | 2.38 in. |
| April | 34.3 °F | 63.2 °F | 1.23 in. |
| May | 40.3 °F | 72.5 °F | 0.99 in. |
| June | 45.4 °F | 81.1 °F | 0.59 in. |
| July | 52.0 °F | 91.0 °F | 0.47 in. |
| August | 50.6 °F | 90.2 °F | 0.21 in. |
| September | 45.2 °F | 83.6 °F | 0.3 in. |
| October | 37.3 °F | 69.9 °F | 1.57 in. |
| November | 31.0 °F | 53.6 °F | 2.74 in. |
| December | 27.3 °F | 44.3 °F | 4.31 in. |
| Annual | 37.7 °F | 67 °F | 22.13 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 8a : 10°F to 15°F |
| Plant Hardiness Zone - 2012 | Zone 7b : 5°F to 10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |