| 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 |
| 1990 Hardiness Zone: | Zone 9b: 25F to 30F |
| Average First Frost Date: | Dec. 1 - Dec. 10 |
| Average Last Frost Date: | Feb. 11 - Feb. 20 |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate |
| Ecoregion: | |
| Heat Zone Days: | 61 - 90 days Over 86°F |
Annual Climate Data for ZIP Code 94509 - Antioch, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 38 | 42 | 44 | 47 | 52 | 57 | 58 | 59 | 57 | 52 | 44 | 38 | 49 |
| Avg Max Temp (°F) | 54 | 60 | 65 | 71 | 77 | 84 | 88 | 88 | 85 | 77 | 64 | 54 | 72 |
| Avg Precip (In.) | 2.95 | 2.69 | 2.28 | .81 | .49 | .1 | .03 | .04 | .24 | .81 | 1.77 | 2.02 | 14.23 |