| 2023 Hardiness Zone: | Zone 10a: 30°F to 35°F |
| 2012 Hardiness Zone: | Zone 10a: 30°F to 35°F |
| 1990 Hardiness Zone: | Zone 10a: 30F to 35F |
| Average First Frost Date: | No Frost |
| Average Last Frost Date: | Frost Rare |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate |
| Ecoregion: | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 94030 - Millbrae, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 42 | 44 | 46 | 47 | 50 | 52 | 54 | 54 | 54 | 51 | 47 | 42 | 49 |
| Avg Max Temp (°F) | 57 | 61 | 63 | 67 | 69 | 73 | 74 | 75 | 75 | 72 | 64 | 57 | 67 |
| Avg Precip (In.) | 4.89 | 4.3 | 3.58 | 1.38 | .51 | .14 | .04 | .07 | .24 | 1.23 | 3.15 | 3.27 | 22.82 |