Upland, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 11.3 °C (low) to 25.3 °C (high). Annual precipitation averages 429.8 Millimeters. Upland is located in USDA Plant Hardiness Zone 10a.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.7 °C | 19.2 °C | 90.68 mm |
| February | 7.1 °C | 19.4 °C | 116.08 mm |
| March | 8.1 °C | 21.2 °C | 70.36 mm |
| April | 9.4 °C | 23.2 °C | 21.84 mm |
| May | 11.6 °C | 25.3 °C | 13.97 mm |
| June | 13.9 °C | 28.9 °C | 3.05 mm |
| July | 16.6 °C | 32.6 °C | 1.78 mm |
| August | 17.2 °C | 33.6 °C | 0.51 mm |
| September | 16.2 °C | 31.9 °C | 3.3 mm |
| October | 12.9 °C | 27.2 °C | 18.8 mm |
| November | 9.1 °C | 22.9 °C | 25.15 mm |
| December | 6.6 °C | 18.6 °C | 64.26 mm |
| Annual | 11.3 °C | 25.3 °C | 429.78 mm |
| Average First Frost Date | No Frost |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 10a : -1.1°C to 1.7°C |
| Plant Hardiness Zone - 2012 | Zone 9b : -3.9°C to -1.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |