Forest Ranch, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 8.9 °C (low) to 21.4 °C (high). Annual precipitation averages 1359.9 Millimeters. Forest Ranch is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Dec. 11 - Dec. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.1 °C | 12.2 °C | 246.63 mm |
| February | 3.5 °C | 13.2 °C | 246.13 mm |
| March | 4.7 °C | 15.6 °C | 191.52 mm |
| April | 6.1 °C | 18.2 °C | 113.79 mm |
| May | 9.6 °C | 23.1 °C | 64.01 mm |
| June | 13.6 °C | 28.6 °C | 21.59 mm |
| July | 17 °C | 33.1 °C | 1.27 mm |
| August | 16.3 °C | 32.7 °C | 3.05 mm |
| September | 14.8 °C | 29.9 °C | 10.67 mm |
| October | 10.3 °C | 23.2 °C | 67.56 mm |
| November | 5.4 °C | 15.5 °C | 127.76 mm |
| December | 2.7 °C | 11.3 °C | 265.94 mm |
| Annual | 8.9 °C | 21.4 °C | 1359.92 mm |
| Average First Frost Date | Dec. 11 - Dec. 20 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |