Martell, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 47.6 °F (low) to 71.7 °F (high). Annual precipitation averages 30.9 Inches. Martell is located in USDA Plant Hardiness Zone 9b. 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 | 37.3 °F | 54.3 °F | 5.85 in. |
| February | 39.0 °F | 57.4 °F | 5.32 in. |
| March | 41.4 °F | 61.4 °F | 4.59 in. |
| April | 43.3 °F | 66.1 °F | 2.89 in. |
| May | 48.6 °F | 75.2 °F | 1.67 in. |
| June | 54.5 °F | 85.1 °F | 0.31 in. |
| July | 59.8 °F | 92.5 °F | 0.02 in. |
| August | 60.5 °F | 90.9 °F | 0.08 in. |
| September | 57.5 °F | 85.6 °F | 0.25 in. |
| October | 49.7 °F | 75.5 °F | 1.57 in. |
| November | 42.2 °F | 62.3 °F | 2.9 in. |
| December | 37.6 °F | 54.0 °F | 5.47 in. |
| Annual | 47.6 °F | 71.7 °F | 30.92 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 9b : 25°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 9b : 25°F to 20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |