Westwood, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 31.8 °F (low) to 60 °F (high). Annual precipitation averages 40.1 Inches. Westwood is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.0 °F | 42.1 °F | 7.22 in. |
| February | 21.2 °F | 44.5 °F | 6.41 in. |
| March | 24.7 °F | 49.7 °F | 6.06 in. |
| April | 29.2 °F | 53.6 °F | 3.26 in. |
| May | 35.6 °F | 63.3 °F | 2.03 in. |
| June | 41.1 °F | 73.1 °F | 0.91 in. |
| July | 46.9 °F | 82.5 °F | 0.32 in. |
| August | 45.0 °F | 81.8 °F | 0.28 in. |
| September | 39.4 °F | 75.7 °F | 0.39 in. |
| October | 32.1 °F | 63.0 °F | 2.03 in. |
| November | 25.5 °F | 49.6 °F | 3.91 in. |
| December | 20.3 °F | 40.8 °F | 7.23 in. |
| Annual | 31.8 °F | 60 °F | 40.05 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |