Portola Valley, CA Weather & Growing Conditions
This Afternoon
81°F
Sunny
Sunny. High near 81, with temperatures falling to around 76 in the afternoon. West northwest wind 3 to 7 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 81°F | Sunny | 3 to 7 mph WNW | 0% |
| Tonight | 54°F | Partly Cloudy | 3 to 7 mph WSW | 0% |
| Sunday | 73°F | Mostly Cloudy | 2 to 6 mph WSW | 2% |
| Sunday Night | 54°F | Mostly Cloudy | 2 to 6 mph WSW | 2% |
| Monday | 75°F | Mostly Sunny | 5 mph WSW | 1% |
| Monday Night | 54°F | Partly Cloudy | 5 mph WSW | 1% |
| Tuesday | 77°F | Mostly Sunny | 1 to 5 mph W | 1% |
| Tuesday Night | 54°F | Mostly Clear | 1 to 5 mph W | 0% |
| Wednesday | 87°F | Sunny | 1 to 5 mph W | 0% |
| Wednesday Night | 60°F | Mostly Clear | 0 to 5 mph NNW | 0% |
| Thursday | 90°F | Sunny | 0 to 5 mph NW | 0% |
| Thursday Night | 60°F | Mostly Clear | 5 mph W | 0% |
| Friday | 84°F | Sunny | 2 to 7 mph W | 0% |
| Friday Night | 56°F | Mostly Clear | 2 to 7 mph W | 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 Sep 20, 2026.