| 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: | Dec. 11 - Dec. 20 | |
| Average Last Frost Date: | Feb. 11 - Feb. 20 | |
| 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 92376 - Rialto, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 42 | 43 | 44 | 47 | 52 | 56 | 61 | 62 | 59 | 53 | 45 | 41 | 50 |
| Avg Max Temp (°F) | 66 | 68 | 69 | 75 | 79 | 87 | 94 | 95 | 90 | 82 | 72 | 67 | 79 |
| Avg Precip (In.) | 3.62 | 3.65 | 3.4 | .9 | .46 | .11 | .05 | .21 | .39 | .6 | 1.22 | 1.9 | 16.5 |