Lake Forest, California has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 53.1 °F (low) to 75.1 °F (high). Annual precipitation averages 14.5 Inches. Lake Forest is located in USDA Plant Hardiness Zone 10b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 46.2 °F | 67.9 °F | 2.9 in. |
| February | 46.3 °F | 67.8 °F | 3.74 in. |
| March | 47.9 °F | 69.7 °F | 2.17 in. |
| April | 49.9 °F | 72.0 °F | 0.9 in. |
| May | 54.2 °F | 73.7 °F | 0.32 in. |
| June | 57.7 °F | 77.7 °F | 0.15 in. |
| July | 61.3 °F | 83.2 °F | 0.1 in. |
| August | 61.9 °F | 85.1 °F | 0.02 in. |
| September | 60.3 °F | 84.4 °F | 0.12 in. |
| October | 55.9 °F | 79.4 °F | 0.63 in. |
| November | 49.8 °F | 73.3 °F | 1.04 in. |
| December | 45.5 °F | 67.2 °F | 2.43 in. |
| Annual | 53.1 °F | 75.1 °F | 14.52 in. |
| Average First Frost Date | No Frost |
| Average Last Frost Date | |
| Average Days With Frost | Frost Free |
| Plant Hardiness Zone | Zone 10b : 35°F to 30°F |
| Plant Hardiness Zone - 2012 | Zone 10a : 30°F to 25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |