Topanga, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 12.4 °C (low) to 25.1 °C (high). Annual precipitation averages 584.7 Millimeters. 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 | 9.6 °C | 19.5 °C | 157.48 mm |
| February | 9 °C | 19.5 °C | 143.26 mm |
| March | 9.6 °C | 20.8 °C | 87.88 mm |
| April | 10.5 °C | 23.7 °C | 27.18 mm |
| May | 12.3 °C | 25.4 °C | 13.72 mm |
| June | 13.9 °C | 27.7 °C | 2.03 mm |
| July | 16.1 °C | 30.5 °C | 1.02 mm |
| August | 16.7 °C | 31.7 °C | 0.25 mm |
| September | 16.3 °C | 31.6 °C | 2.54 mm |
| October | 14.4 °C | 28.1 °C | 21.34 mm |
| November | 11.6 °C | 23.1 °C | 29.97 mm |
| December | 9.3 °C | 19.3 °C | 98.04 mm |
| Annual | 12.4 °C | 25.1 °C | 584.71 mm |
| 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 : 1.7°C to 4.4°C |
| Plant Hardiness Zone - 2012 | Zone 10b : 1.7°C to 4.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |