| 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: | Dec. 21 - Dec. 31 |
| Average Last Frost Date: | Feb. 11 - Feb. 20 |
| 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 94518 - Concord, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 37 | 40 | 41 | 44 | 48 | 53 | 55 | 55 | 53 | 48 | 42 | 37 | 46 |
| Avg Max Temp (°F) | 55 | 60 | 64 | 70 | 76 | 82 | 87 | 88 | 84 | 76 | 64 | 55 | 72 |
| Avg Precip (In.) | 4.14 | 3.49 | 2.59 | 1.3 | .69 | .12 | .04 | .03 | .16 | 1.07 | 2.09 | 2.84 | 18.55 |