Portola Valley, CA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Portola Valley, a town in San Mateo County, California.

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 for Portola Valley

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) for Portola Valley (37.365, -122.233). Updated through the day.

Growing snapshot for Portola Valley

Last spring frost

Feb 25

First fall frost

Nov 25

Growing season

274 days

Hardiness zone

More local growing data for Portola Valley: nearby ZIP 94028 weather · frost dates · planting calendar · California frost dates

Nearby towns & communities

Atherton Baywood Park Belmont Brisbane Broadmoor Burlingame Colma Daly City El Granada Emerald Lake Hills Foster City Half Moon Bay Highlands Hillsborough La Honda Ladera Loma Mar Millbrae Montara Moss Beach North Fair Oaks Pacifica Pescadero Redwood City San Bruno San Carlos San Mateo South San Francisco West Menlo Park Woodside

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Climate data from the nearest NOAA station, Woodside Fire Stn 1, Ca (4.4 mi from Portola Valley). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.