| 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: | Jan. 11 - Jan. 20 | |
| Average Last Frost Date: | Jan. 21 - Jan. 31 | |
| 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 92335 - Fontana, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 43 | 45 | 45 | 48 | 52 | 56 | 60 | 61 | 59 | 54 | 47 | 42 | 51 |
| Avg Max Temp (°F) | 66 | 69 | 70 | 75 | 79 | 87 | 94 | 95 | 90 | 82 | 73 | 67 | 79 |
| Avg Precip (In.) | 3.6 | 3.55 | 3.51 | .74 | .28 | .05 | .01 | .15 | .31 | .36 | 1.27 | 1.82 | 15.65 |