Topanga, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 54.4 °F (low) to 77.1 °F (high). Annual precipitation averages 23 Inches. Topanga is located in USDA Plant Hardiness Zone 10b. The growing season typically runs from the last frost around Jan. 21 - Jan. 31 through the first frost around Jan. 1 - Jan. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 49.2 °F | 67.1 °F | 6.2 in. |
| February | 48.2 °F | 67.1 °F | 5.64 in. |
| March | 49.3 °F | 69.4 °F | 3.46 in. |
| April | 50.9 °F | 74.7 °F | 1.07 in. |
| May | 54.1 °F | 77.8 °F | 0.54 in. |
| June | 57.1 °F | 81.9 °F | 0.08 in. |
| July | 61.0 °F | 86.9 °F | 0.04 in. |
| August | 62.0 °F | 89.1 °F | 0.01 in. |
| September | 61.3 °F | 88.9 °F | 0.1 in. |
| October | 57.9 °F | 82.6 °F | 0.84 in. |
| November | 52.9 °F | 73.5 °F | 1.18 in. |
| December | 48.8 °F | 66.7 °F | 3.86 in. |
| Annual | 54.4 °F | 77.1 °F | 23.02 in. |
| Average First Frost Date | Jan. 1 - Jan. 10 |
| Average Last Frost Date | Jan. 21 - Jan. 31 |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 10b : 35°F to 30°F |
| Plant Hardiness Zone - 2012 | Zone 10b : 35°F to 30°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |