Westmorland, California has a Hot Desert Climate climate (Köppen classification: BWh). Average annual temperatures range from 57.8 °F (low) to 87.1 °F (high). Annual precipitation averages 2.4 Inches. Westmorland is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 41.4 °F | 69.3 °F | 0.44 in. |
| February | 44.5 °F | 72.8 °F | 0.46 in. |
| March | 49.4 °F | 78.7 °F | 0.3 in. |
| April | 54.5 °F | 84.7 °F | 0.08 in. |
| May | 61.1 °F | 92.3 °F | 0.04 in. |
| June | 67.9 °F | 100.9 °F | 0.0 in. |
| July | 76.3 °F | 105.2 °F | 0.09 in. |
| August | 77.5 °F | 105.1 °F | 0.16 in. |
| September | 71.2 °F | 100.7 °F | 0.19 in. |
| October | 60.2 °F | 90.0 °F | 0.12 in. |
| November | 48.2 °F | 77.6 °F | 0.14 in. |
| December | 41.3 °F | 68.0 °F | 0.4 in. |
| Annual | 57.8 °F | 87.1 °F | 2.42 in. |
| Average First Frost Date | No Frost |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9b : 25°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 9b : 25°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | BWh - Hot Desert Climate |