| 2023 Hardiness Zone: | Zone 9b: 25°F to 30°F |
| 2012 Hardiness Zone: | Zone 9b: 25°F to 30°F |
| 1990 Hardiness Zone: | Zone 9b: 25F to 30F |
| Average First Frost Date: | Jan. 1 - Jan. 10 |
| Average Last Frost Date: | Jan. 21 - Jan. 31 |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate |
| Ecoregion: | |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 94590 - Vallejo, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 39 | 42 | 44 | 46 | 49 | 53 | 55 | 55 | 54 | 49 | 44 | 39 | 47 |
| Avg Max Temp (°F) | 56 | 61 | 64 | 69 | 73 | 77 | 80 | 80 | 79 | 75 | 64 | 57 | 70 |
| Avg Precip (In.) | 5.04 | 4.52 | 3.29 | 1.34 | .75 | .17 | .05 | .1 | .3 | 1.36 | 2.91 | 3.55 | 23.36 |