Willows, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 9.6 °C (low) to 24.3 °C (high). Annual precipitation averages 504 Millimeters. Willows is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.7 °C | 13.7 °C | 111 mm |
| February | 5.1 °C | 16.6 °C | 97.03 mm |
| March | 6.4 °C | 19.3 °C | 66.8 mm |
| April | 7.8 °C | 23.2 °C | 28.45 mm |
| May | 11.7 °C | 27.6 °C | 25.4 mm |
| June | 15.1 °C | 31.8 °C | 7.37 mm |
| July | 16.6 °C | 34.4 °C | 0.25 mm |
| August | 15.7 °C | 33.9 °C | 1.02 mm |
| September | 13.8 °C | 32.1 °C | 2.29 mm |
| October | 10.2 °C | 26.9 °C | 21.34 mm |
| November | 5.9 °C | 18.6 °C | 49.28 mm |
| December | 3.5 °C | 13.5 °C | 93.73 mm |
| Annual | 9.6 °C | 24.3 °C | 503.96 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 20-30 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 |