Hopland, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 7 °C (low) to 22.7 °C (high). Annual precipitation averages 977.6 Millimeters. Hopland is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Dec. 1 - Dec. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.9 °C | 14.1 °C | 192.02 mm |
| February | 3.4 °C | 15.8 °C | 180.34 mm |
| March | 4.6 °C | 18.2 °C | 129.03 mm |
| April | 5.8 °C | 20 °C | 66.55 mm |
| May | 8.2 °C | 24.2 °C | 32.51 mm |
| June | 10.8 °C | 28.4 °C | 8.89 mm |
| July | 12.3 °C | 32.4 °C | 0.51 mm |
| August | 11.8 °C | 32.2 °C | 1.27 mm |
| September | 10.2 °C | 30.3 °C | 3.56 mm |
| October | 7.4 °C | 25.1 °C | 49.78 mm |
| November | 4.4 °C | 18 °C | 100.84 mm |
| December | 2.5 °C | 13.7 °C | 212.34 mm |
| Annual | 7 °C | 22.7 °C | 977.64 mm |
| Average First Frost Date | Dec. 1 - Dec. 10 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 20-30 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 |