| 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 9b: 25F to 30F | |
| 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 91730 - Rancho Cucamonga, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 41 | 43 | 43 | 45 | 50 | 54 | 58 | 59 | 58 | 52 | 45 | 41 | 49 |
| Avg Max Temp (°F) | 64 | 67 | 68 | 73 | 77 | 85 | 92 | 92 | 88 | 80 | 71 | 65 | 77 |
| Avg Precip (In.) | 4.39 | 4.51 | 4.3 | .99 | .47 | .11 | .01 | .15 | .42 | .63 | 1.49 | 2.39 | 19.88 |