Foresthill, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 47.8 °F (low) to 68.6 °F (high). Annual precipitation averages 53.3 Inches. Foresthill is located in USDA Plant Hardiness Zone 9a. 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 | 36.1 °F | 52.1 °F | 9.4 in. |
| February | 35.9 °F | 53.5 °F | 9.08 in. |
| March | 38.2 °F | 58.1 °F | 7.75 in. |
| April | 40.8 °F | 63.2 °F | 4.57 in. |
| May | 47.8 °F | 71.6 °F | 2.81 in. |
| June | 56.4 °F | 81.8 °F | 0.81 in. |
| July | 64.2 °F | 89.7 °F | 0.0 in. |
| August | 65.0 °F | 89.5 °F | 0.1 in. |
| September | 59.0 °F | 83.5 °F | 0.58 in. |
| October | 51.2 °F | 71.2 °F | 2.73 in. |
| November | 42.2 °F | 58.2 °F | 5.43 in. |
| December | 36.2 °F | 50.3 °F | 10.04 in. |
| Annual | 47.8 °F | 68.6 °F | 53.3 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 9a : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 9a : 20°F to 25°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |