Westmorland, California has a Hot Desert Climate climate (Köppen classification: BWh). Average annual temperatures range from 14.3 °C (low) to 30.6 °C (high). Annual precipitation averages 61.5 Millimeters. Westmorland is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 5.2 °C | 20.7 °C | 11.18 mm |
| February | 6.9 °C | 22.7 °C | 11.68 mm |
| March | 9.7 °C | 25.9 °C | 7.62 mm |
| April | 12.5 °C | 29.3 °C | 2.03 mm |
| May | 16.2 °C | 33.5 °C | 1.02 mm |
| June | 19.9 °C | 38.3 °C | 0 mm |
| July | 24.6 °C | 40.7 °C | 2.29 mm |
| August | 25.3 °C | 40.6 °C | 4.06 mm |
| September | 21.8 °C | 38.2 °C | 4.83 mm |
| October | 15.7 °C | 32.2 °C | 3.05 mm |
| November | 9 °C | 25.3 °C | 3.56 mm |
| December | 5.2 °C | 20 °C | 10.16 mm |
| Annual | 14.3 °C | 30.6 °C | 61.48 mm |
| Average First Frost Date | No Frost |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9b : -3.9°C to -1.1°C |
| Plant Hardiness Zone - 2012 | Zone 9b : -3.9°C to -1.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | BWh - Hot Desert Climate |