| 2023 Hardiness Zone: | Zone 10a: 30°F to 35°F | |
| 2012 Hardiness Zone: | Zone 9b: 25°F to 30°F Zone 10a: 30°F to 35°F | |
| 1990 Hardiness Zone: | Zone 10a: 30F to 35F | |
| Average First Frost Date: | No Frost | |
| Average Last Frost Date: | No Frost | |
| Koppen-Geiger Climate Zone: | Csa - Hot-Summer Mediterranean Climate | |
| Ecoregion: | ||
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 91 - 120 days Over 86°F |
Annual Climate Data for ZIP Code 91786 - Upland, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 41 | 42 | 43 | 45 | 50 | 54 | 58 | 59 | 57 | 51 | 45 | 40 | 49 |
| Avg Max Temp (°F) | 63 | 65 | 67 | 72 | 76 | 83 | 90 | 90 | 86 | 78 | 70 | 64 | 75 |
| Avg Precip (In.) | 4.95 | 5.2 | 4.67 | 1.18 | .58 | .13 | .02 | .18 | .49 | .83 | 1.63 | 2.72 | 22.59 |