| 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 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. 11 - Dec. 20 |
| Average Last Frost Date: | Mar. 1 - Mar. 10 |
| 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 94598 - Walnut Creek, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 37 | 39 | 41 | 43 | 48 | 52 | 54 | 55 | 52 | 47 | 42 | 37 | 46 |
| Avg Max Temp (°F) | 55 | 60 | 64 | 70 | 75 | 82 | 87 | 87 | 83 | 76 | 64 | 55 | 71 |
| Avg Precip (In.) | 4.25 | 3.86 | 2.85 | 1.4 | .75 | .11 | .05 | .08 | .2 | 1.2 | 2.19 | 2.82 | 19.76 |