Cassel, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 1.7 °C (low) to 19.5 °C (high). Annual precipitation averages 516.6 Millimeters. Cassel is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.1 °C | 8.2 °C | 69.09 mm |
| February | -3.2 °C | 10.5 °C | 77.47 mm |
| March | -1.3 °C | 13.6 °C | 67.56 mm |
| April | 0.5 °C | 17 °C | 45.97 mm |
| May | 4.1 °C | 22.3 °C | 40.13 mm |
| June | 7.2 °C | 27.6 °C | 17.53 mm |
| July | 9.8 °C | 32.7 °C | 4.06 mm |
| August | 8.3 °C | 32.2 °C | 4.32 mm |
| September | 5.1 °C | 28.7 °C | 10.41 mm |
| October | 0.7 °C | 21.3 °C | 33.53 mm |
| November | -2.2 °C | 12.4 °C | 60.71 mm |
| December | -4.3 °C | 7.3 °C | 85.85 mm |
| Annual | 1.7 °C | 19.5 °C | 516.63 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |