Martell, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 8.7 °C (low) to 22 °C (high). Annual precipitation averages 785.4 Millimeters. 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 | 2.9 °C | 12.4 °C | 148.59 mm |
| February | 3.9 °C | 14.1 °C | 135.13 mm |
| March | 5.2 °C | 16.3 °C | 116.59 mm |
| April | 6.3 °C | 18.9 °C | 73.41 mm |
| May | 9.2 °C | 24 °C | 42.42 mm |
| June | 12.5 °C | 29.5 °C | 7.87 mm |
| July | 15.4 °C | 33.6 °C | 0.51 mm |
| August | 15.8 °C | 32.7 °C | 2.03 mm |
| September | 14.2 °C | 29.8 °C | 6.35 mm |
| October | 9.8 °C | 24.2 °C | 39.88 mm |
| November | 5.7 °C | 16.8 °C | 73.66 mm |
| December | 3.1 °C | 12.2 °C | 138.94 mm |
| Annual | 8.7 °C | 22 °C | 785.38 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 9b : -3.9°C to -1.1°C |
| Plant Hardiness Zone - 2012 | Zone 9b : -3.9°C to -1.1°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |