Portola Valley, CA Weather & Growing Conditions
Overnight
56°F
Mostly Clear
Mostly clear, with a low around 56. South southwest wind around 2 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 56°F | Mostly Clear | 2 mph SSW | 0% |
| Tuesday | 92°F | Haze then Sunny | 1 to 5 mph SW | 0% |
| Tuesday Night | 56°F | Clear | 1 to 5 mph SW | 0% |
| Wednesday | 89°F | Sunny | 1 to 5 mph WSW | 0% |
| Wednesday Night | 57°F | Mostly Clear | 0 to 5 mph WSW | 0% |
| Thursday | 87°F | Sunny | 0 to 5 mph SW | 0% |
| Thursday Night | 58°F | Mostly Clear | 0 to 5 mph NW | 0% |
| Friday | 91°F | Sunny | 0 to 5 mph NW | 0% |
| Friday Night | 60°F | Mostly Clear | 1 to 5 mph NW | 0% |
| Saturday | 91°F | Sunny | 0 to 5 mph WNW | 0% |
| Saturday Night | 61°F | Mostly Clear | 5 mph W | 0% |
| Sunday | 86°F | Sunny | 2 to 6 mph W | 0% |
| Sunday Night | 56°F | Mostly Clear | 6 mph W | 0% |
| Monday | 80°F | Sunny | 3 to 7 mph WSW | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Portola Valley, CA
Last spring frost
Feb 25
First fall frost
Nov 25
Growing season
274 days
Hardiness zone
9b
Explore more for Portola Valley, CA: full frost dates · planting calendar · California frost dates
Climate data from the nearest NOAA station, Woodside Fire Stn 1, Ca (4.4 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.