Brea, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 54.2 °F (low) to 77.4 °F (high). Annual precipitation averages 14.1 Inches. Brea is located in USDA Plant Hardiness Zone 10a.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 46.1 °F | 68.8 °F | 3.28 in. |
| February | 47.0 °F | 68.9 °F | 3.76 in. |
| March | 49.3 °F | 71.0 °F | 2.12 in. |
| April | 51.5 °F | 75.5 °F | 0.69 in. |
| May | 55.9 °F | 77.1 °F | 0.3 in. |
| June | 59.4 °F | 80.8 °F | 0.08 in. |
| July | 63.1 °F | 86.4 °F | 0.04 in. |
| August | 63.7 °F | 88.6 °F | 0.0 in. |
| September | 62.0 °F | 87.2 °F | 0.13 in. |
| October | 57.1 °F | 82.3 °F | 0.53 in. |
| November | 50.3 °F | 74.5 °F | 0.78 in. |
| December | 45.4 °F | 68.2 °F | 2.35 in. |
| Annual | 54.2 °F | 77.4 °F | 14.06 in. |
| Average First Frost Date | No Frost |
| Average Last Frost Date | |
| Average Days With Frost | Frost Free |
| Plant Hardiness Zone | Zone 10a : 30°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 10a : 30°F to 25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |