| 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 Zone 10a: 30°F to 35°F |
| 1990 Hardiness Zone: | Zone 9b: 25F to 30F |
| Average First Frost Date: | Jan. 11 - Jan. 20 |
| Average Last Frost Date: | Jan. 21 - Jan. 31 |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate |
| Ecoregion: | |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 94303 - Palo Alto, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 40 | 43 | 45 | 47 | 51 | 54 | 56 | 57 | 55 | 50 | 44 | 39 | 48 |
| Avg Max Temp (°F) | 58 | 62 | 65 | 69 | 73 | 78 | 80 | 80 | 78 | 74 | 64 | 58 | 70 |
| Avg Precip (In.) | 3.43 | 3.31 | 2.74 | .97 | .36 | .11 | .04 | .08 | .2 | .89 | 1.92 | 2.35 | 16.41 |