Portola Valley, CA Weather & Growing Conditions
Overnight
49°F
Chance Light Rain
A chance of rain before 4am. Partly cloudy, with a low around 49. North northeast wind around 3 mph. Chance of precipitation is 30%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 49°F | Chance Light Rain | 3 mph NNE | 25% |
| Wednesday | 66°F | Sunny | 2 to 12 mph NNE | 2% |
| Wednesday Night | 50°F | Mostly Cloudy | 1 to 12 mph NW | 2% |
| Thursday | 71°F | Mostly Sunny | 2 mph NNW | 0% |
| Thursday Night | 49°F | Clear | 0 to 3 mph NNE | 0% |
| Friday | 74°F | Sunny | 2 mph NNE | 0% |
| Friday Night | 51°F | Mostly Clear | 2 mph N | 0% |
| Saturday | 76°F | Sunny | 1 mph N | 0% |
| Saturday Night | 50°F | Mostly Clear | 2 mph NNW | 0% |
| Sunday | 72°F | Sunny | 2 mph N | 0% |
| Sunday Night | 53°F | Partly Cloudy | 2 mph NW | 0% |
| Monday | 70°F | Mostly Sunny | 3 mph NW | 2% |
| Monday Night | 52°F | Partly Cloudy | 3 mph NW | 2% |
| Tuesday | 70°F | Sunny | 2 mph NNW | 6% |
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 Nov 4, 2026.