Rancho Cucamonga, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 52.5 °F (low) to 78 °F (high). Annual precipitation averages 16.6 Inches. Rancho Cucamonga is located in USDA Plant Hardiness Zone 10a.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 44.1 °F | 66.7 °F | 3.56 in. |
| February | 44.7 °F | 67.0 °F | 4.45 in. |
| March | 46.9 °F | 70.2 °F | 2.71 in. |
| April | 49.2 °F | 74.2 °F | 0.88 in. |
| May | 53.4 °F | 78.2 °F | 0.43 in. |
| June | 57.5 °F | 84.7 °F | 0.09 in. |
| July | 62.4 °F | 91.3 °F | 0.05 in. |
| August | 63.4 °F | 93.0 °F | 0.03 in. |
| September | 61.4 °F | 90.0 °F | 0.17 in. |
| October | 55.5 °F | 81.5 °F | 0.74 in. |
| November | 48.3 °F | 73.5 °F | 0.97 in. |
| December | 43.6 °F | 65.7 °F | 2.49 in. |
| Annual | 52.5 °F | 78 °F | 16.57 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 |