Average annual temperature is 14.3 °C
Absolute maximum temperature: 35.9 °C
Absolute minimum temperature: 1.6 °C
Number of sunny days: 255 days
Number of rainy days: 110 days
Look at detailed online map of Portola Valley
* Weather data for Portola Valley United States is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 18.4 | 17.6 | 20.3 | 28.9 | 28.6 | 32.1 | 35.9 | 34.7 | 29.7 | 33.8 | 25.0 | 18.4 |
| Average daytime temperature (°C) | 13.6 | 13.4 | 13.7 | 18.4 | 20.1 | 23.4 | 29.1 | 29.3 | 25.3 | 25.1 | 18.9 | 15.5 |
| Average temperature (°C) | 9.8 | 8.5 | 9.0 | 12.0 | 14.0 | 16.2 | 20.2 | 20.9 | 18.1 | 17.8 | 13.6 | 11.3 |
| Average night temperature (°C) | 7.0 | 4.8 | 5.9 | 7.8 | 10.0 | 11.4 | 13.5 | 15.3 | 13.1 | 12.8 | 9.5 | 8.1 |
| Absolute minimum temperature (°C) | 2.1 | 1.6 | 2.0 | 4.3 | 6.8 | 8.8 | 11.5 | 12.5 | 9.7 | 6.4 | 5.0 | 4.3 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 14.0 | 14.0 | 14.0 | 12.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 9.9 | 10.8 | 12.0 | 13.2 | 14.2 | 14.7 | 14.5 | 13.6 | 12.4 | 11.2 | 10.2 | 9.6 |
| Daylight minimum duration (h) | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 | 9.0 |
| Sunshine mean duration (h) | 6.2 | 7.8 | 7.8 | 10.9 | 11.0 | 12.5 | 13.0 | 12.2 | 10.8 | 9.5 | 8.1 | 6.1 |
| Precipitation (mm) | 268 | 117 | 204 | 7 | 44 | 0 | 0 | 0 | 5 | 6 | 71 | 145 |
| Sunny days | 10 | 15 | 7 | 25 | 22 | 29 | 31 | 30 | 25 | 26 | 20 | 15 |
| Rainy days | 21 | 13 | 24 | 5 | 9 | 1 | 0 | 1 | 5 | 5 | 10 | 16 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit Portola Valley during the most sunny months:
The largest precipitation sum in Portola Valley is at