Foster City, CA Weather & Growing Conditions
Overnight
58°F
Partly Cloudy
Partly cloudy, with a low around 58. West southwest wind around 7 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 58°F | Partly Cloudy | 7 mph WSW | 0% |
| Saturday | 78°F | Sunny | 3 to 13 mph W | 0% |
| Saturday Night | 57°F | Partly Cloudy | 5 to 12 mph WSW | 1% |
| Sunday | 72°F | Mostly Cloudy | 5 to 10 mph W | 3% |
| Sunday Night | 58°F | Mostly Cloudy | 3 to 10 mph W | 3% |
| Monday | 75°F | Mostly Sunny | 3 to 12 mph WSW | 1% |
| Monday Night | 57°F | Partly Cloudy | 3 to 12 mph WSW | 1% |
| Tuesday | 76°F | Mostly Sunny | 3 to 10 mph WSW | 0% |
| Tuesday Night | 57°F | Mostly Clear | 1 to 10 mph WSW | 0% |
| Wednesday | 84°F | Sunny | 1 to 9 mph W | 0% |
| Wednesday Night | 60°F | Mostly Clear | 1 to 9 mph WSW | 0% |
| Thursday | 85°F | Sunny | 1 to 10 mph W | 0% |
| Thursday Night | 59°F | Mostly Clear | 1 to 10 mph WSW | 0% |
| Friday | 80°F | Mostly Sunny | 1 to 12 mph WSW | 0% |
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 Sep 19, 2026.