| 2023 Hardiness Zone: | Zone 9a: 20°F to 25°F Zone 9b: 25°F to 30°F |
| 2012 Hardiness Zone: | Zone 9a: 20°F to 25°F Zone 9b: 25°F to 30°F |
| 1990 Hardiness Zone: | Zone 9a: 20F to 25F |
| Average First Frost Date: | Nov. 11 - Nov. 20 |
| Average Last Frost Date: | Apr. 11 - Apr. 20 |
| Koppen-Geiger Climate Zone: | Csa - Hot-Summer Mediterranean Climate |
| Ecoregion: | |
| Heat Zone Days: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 95949 - Grass Valley, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 34 | 36 | 38 | 41 | 47 | 53 | 58 | 57 | 53 | 46 | 38 | 34 | 45 |
| Avg Max Temp (°F) | 54 | 57 | 60 | 66 | 74 | 83 | 90 | 90 | 84 | 75 | 60 | 54 | 71 |
| Avg Precip (In.) | 8.51 | 7.84 | 7.34 | 3.35 | 1.79 | .56 | .12 | .16 | .94 | 2.51 | 5.93 | 6.9 | 45.96 |