| 2023 Hardiness Zone: | Zone 9a: 20°F to 25°F Zone 9b: 25°F to 30°F Zone 10a: 30°F to 35°F |
| 2012 Hardiness Zone: | Zone 9a: 20°F to 25°F Zone 9b: 25°F to 30°F |
| 1990 Hardiness Zone: | Zone 9b: 25F to 30F |
| Average First Frost Date: | Nov. 11 - Nov. 20 |
| Average Last Frost Date: | Mar. 21 - Mar. 31 |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate |
| Ecoregion: | |
| Heat Zone Days: | 91 - 120 days Over 86°F |
Annual Climate Data for ZIP Code 94515 - Calistoga, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 38 | 40 | 41 | 43 | 47 | 51 | 54 | 53 | 52 | 48 | 42 | 37 | 46 |
| Avg Max Temp (°F) | 55 | 57 | 61 | 68 | 75 | 83 | 88 | 87 | 83 | 75 | 61 | 55 | 71 |
| Avg Precip (In.) | 7.74 | 7.45 | 5.83 | 2.12 | .88 | .22 | .09 | .11 | .46 | 1.9 | 5.12 | 5.73 | 37.66 |