Foster City, CA Weather & Growing Conditions
Tonight
51°F
Chance Light Rain then Mostly Cloudy
A chance of rain before 10pm. Mostly cloudy, with a low around 51. East southeast wind around 7 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 51°F | Chance Light Rain then Mostly Cloudy | 7 mph ESE | 41% |
| Wednesday | 68°F | Sunny | 3 to 13 mph N | 2% |
| Wednesday Night | 52°F | Mostly Cloudy then Patchy Fog | 2 to 13 mph NW | 0% |
| Thursday | 70°F | Patchy Fog then Sunny | 2 to 8 mph NNW | 0% |
| Thursday Night | 52°F | Mostly Clear then Patchy Fog | 2 to 8 mph WNW | 0% |
| Friday | 73°F | Patchy Fog then Sunny | 2 to 6 mph NNE | 0% |
| Friday Night | 52°F | Clear | 0 to 6 mph NNW | 0% |
| Saturday | 76°F | Sunny | 2 mph NNE | 0% |
| Saturday Night | 54°F | Mostly Clear | 1 to 6 mph WNW | 0% |
| Sunday | 74°F | Mostly Sunny | 1 to 6 mph NNW | 0% |
| Sunday Night | 54°F | Partly Cloudy | 1 to 6 mph WNW | 0% |
| Monday | 72°F | Partly Sunny | 1 to 8 mph WNW | 1% |
| Monday Night | 53°F | Mostly Cloudy | 1 to 8 mph NW | 2% |
| Tuesday | 72°F | Mostly Sunny | 1 to 6 mph N | 7% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Foster City, CA
Last spring frost
Jan 17
First fall frost
Dec 12
Growing season
333 days
Hardiness zone
10a
Explore more for Foster City, CA: full frost dates · planting calendar · California frost dates
Climate data from the nearest NOAA station, Redwood City, Ca (5.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.