Foster City, CA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Foster City, a city in San Mateo County, California.

Overnight

58°F

Partly Cloudy

Partly cloudy, with a low around 58. Northwest wind around 5 mph.

7-day forecast for Foster City

When	Temp	Forecast	Wind	Precip
Overnight	58°F	Partly Cloudy	5 mph NW	0%
Tuesday	71°F	Haze then Sunny	3 to 14 mph NNW	0%
Tuesday Night	58°F	Mostly Clear	3 to 13 mph NW	0%
Wednesday	69°F	Sunny	3 to 14 mph WNW	0%
Wednesday Night	59°F	Mostly Clear	2 to 14 mph W	0%
Thursday	68°F	Mostly Sunny	2 to 14 mph W	0%
Thursday Night	60°F	Mostly Clear	3 to 14 mph W	0%
Friday	74°F	Sunny	3 to 13 mph WNW	0%
Friday Night	61°F	Mostly Clear	2 to 13 mph W	0%
Saturday	78°F	Sunny	2 to 13 mph W	0%
Saturday Night	62°F	Mostly Clear	5 to 13 mph WSW	0%
Sunday	74°F	Sunny	5 to 14 mph WSW	0%
Sunday Night	60°F	Mostly Clear	8 to 14 mph WSW	0%
Monday	72°F	Mostly Sunny	7 to 15 mph WSW	0%

Forecast source: National Weather Service (api.weather.gov) for Foster City (37.565, -122.251). Updated through the day.

Growing snapshot for Foster City

Last spring frost

Jan 17

First fall frost

Dec 12

Growing season

333 days

Hardiness zone

10a

More local growing data for Foster City: nearby ZIP 94404 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 Half Moon Bay Highlands Hillsborough La Honda Ladera Loma Mar Millbrae Montara Moss Beach North Fair Oaks Pacifica Pescadero Portola Valley 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, Redwood City, Ca (5.7 mi from Foster City). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.