| 2023 Hardiness Zone: | Zone 9b: 25°F to 30°F | |
| 2012 Hardiness Zone: | Zone 9b: 25°F to 30°F | |
| 1990 Hardiness Zone: | Zone 9a: 20F to 25F | |
| Average First Frost Date: | Dec. 1 - Dec. 10 | |
| Average Last Frost Date: | Feb. 21 - Feb. 29 | |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate | |
| Ecoregion: | ||
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 91 - 120 days Over 86°F |
Annual Climate Data for ZIP Code 92508 - Riverside, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 40 | 41 | 43 | 46 | 51 | 55 | 60 | 61 | 58 | 51 | 43 | 39 | 49 |
| Avg Max Temp (°F) | 66 | 68 | 69 | 76 | 80 | 89 | 96 | 96 | 91 | 83 | 74 | 67 | 80 |
| Avg Precip (In.) | 2.94 | 2.85 | 2.65 | .74 | .38 | .13 | .06 | .24 | .37 | .42 | .95 | 1.39 | 13.12 |