Willits, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 4.7 °C (low) to 20.7 °C (high). Annual precipitation averages 1322.3 Millimeters. Willits is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1 °C | 12.8 °C | 253.49 mm |
| February | 1.4 °C | 14.3 °C | 222.76 mm |
| March | 2.2 °C | 16.1 °C | 169.93 mm |
| April | 3.3 °C | 17.2 °C | 93.47 mm |
| May | 5.5 °C | 20.9 °C | 49.53 mm |
| June | 8 °C | 25.8 °C | 16.26 mm |
| July | 10.2 °C | 30.2 °C | 1.02 mm |
| August | 9.5 °C | 30.6 °C | 1.78 mm |
| September | 7.4 °C | 28.7 °C | 5.59 mm |
| October | 4.6 °C | 23.3 °C | 66.04 mm |
| November | 2.4 °C | 16.7 °C | 140.21 mm |
| December | 0.6 °C | 12.2 °C | 302.26 mm |
| Annual | 4.7 °C | 20.7 °C | 1322.34 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |