| 2023 Hardiness Zone: | Zone 9b: 25°F to 30°F 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. 21 - Dec. 31 | |
| Average Last Frost Date: | Feb. 1 - Feb. 10 | |
| 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 92509 - Riverside, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 43 | 45 | 46 | 49 | 53 | 57 | 61 | 62 | 60 | 54 | 46 | 42 | 52 |
| Avg Max Temp (°F) | 68 | 69 | 71 | 76 | 80 | 87 | 94 | 94 | 90 | 83 | 74 | 69 | 80 |
| Avg Precip (In.) | 2.97 | 2.94 | 2.66 | .65 | .22 | .06 | .02 | .15 | .25 | .33 | 1.02 | 1.49 | 12.74 |