| 2023 Hardiness Zone: | Zone 9a: 20°F to 25°F Zone 9b: 25°F to 30°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. 1 - Dec. 10 |
| Average Last Frost Date: | Feb. 21 - Feb. 29 |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate |
| Ecoregion: | |
| Heat Zone Days: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 94599 - Yountville, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 38 | 40 | 42 | 44 | 48 | 52 | 55 | 54 | 53 | 48 | 42 | 37 | 46 |
| Avg Max Temp (°F) | 57 | 61 | 64 | 71 | 77 | 84 | 88 | 87 | 84 | 77 | 64 | 57 | 72 |
| Avg Precip (In.) | 6.46 | 6.05 | 4.55 | 1.55 | .74 | .17 | .05 | .09 | .36 | 1.61 | 4.14 | 4.52 | 30.29 |