Redwood Valley, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.9 °C (low) to 23.1 °C (high). Annual precipitation averages 931.7 Millimeters. Redwood Valley is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.7 °C | 13.9 °C | 183.64 mm |
| February | 3.2 °C | 15.6 °C | 144.27 mm |
| March | 4.3 °C | 18.1 °C | 146.3 mm |
| April | 5.5 °C | 20.3 °C | 66.29 mm |
| May | 7.9 °C | 24.6 °C | 33.27 mm |
| June | 10.5 °C | 29 °C | 11.94 mm |
| July | 12.6 °C | 33.8 °C | 1.02 mm |
| August | 11.9 °C | 33.6 °C | 3.3 mm |
| September | 10.1 °C | 31.5 °C | 4.32 mm |
| October | 7.1 °C | 25.4 °C | 48.77 mm |
| November | 4.2 °C | 17.7 °C | 100.33 mm |
| December | 2.2 °C | 13.5 °C | 188.21 mm |
| Annual | 6.9 °C | 23.1 °C | 931.66 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |