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Foster City, CA weather and climate

San Mateo County, CA · population 32,964 · about 7 ft elevation

Everything below is a 30 year average for 1991-2020, computed from daily climate history at Foster City's own coordinates.

The year at a glance

Sunny days
234
clear or partly cloudy, per year
Precipitation
21 in
per year
Wet days
56
rain or snow per year
Snowfall
0 in
per year
Hot days
20
above 90 °F
Freezing nights
8
at or below 32 °F
Humidity
77%
average relative
Average temperature
59 °F
year round

Monthly temperatures

Average daily high and low for each month, in °F.

Daily highDaily low
406080JanMarMayJulSepNovDaily high, Jan: 59 °FDaily high, Feb: 62 °FDaily high, Mar: 65 °FDaily high, Apr: 68 °FDaily high, May: 72 °FDaily high, Jun: 78 °FDaily high, Jul: 80 °FDaily high, Aug: 80 °FDaily high, Sep: 79 °FDaily high, Oct: 75 °FDaily high, Nov: 65 °FDaily high, Dec: 59 °FDaily low, Jan: 41 °FDaily low, Feb: 43 °FDaily low, Mar: 45 °FDaily low, Apr: 47 °FDaily low, May: 50 °FDaily low, Jun: 53 °FDaily low, Jul: 55 °FDaily low, Aug: 56 °FDaily low, Sep: 54 °FDaily low, Oct: 50 °FDaily low, Nov: 45 °FDaily low, Dec: 41 °F
View monthly temperatures as a table
Monthly temperatures (°F)
CityJanFebMarAprMayJunJulAugSepOctNovDec
Daily high596265687278808079756559
Daily low414345475053555654504541

Monthly precipitation

Total rain plus melted snow for each month, in inches.

0.02.04.0JanMarMayJulSepNovFoster City, Jan: 3.9 inFoster City, Feb: 4.2 inFoster City, Mar: 3.2 inFoster City, Apr: 1.6 inFoster City, May: 0.8 inFoster City, Jun: 0.2 inFoster City, Jul: 0.0 inFoster City, Aug: 0.0 inFoster City, Sep: 0.1 inFoster City, Oct: 0.9 inFoster City, Nov: 2.0 inFoster City, Dec: 3.7 in
View monthly precipitation as a table
Monthly precipitation (inches)
CityJanFebMarAprMayJunJulAugSepOctNovDec
Foster City3.94.23.21.60.80.20.00.00.10.92.03.7

Monthly sunny days

Days each month with clear or partly cloudy skies.

01020JanMarMayJulSepNovFoster City, Jan: 13 daysFoster City, Feb: 13 daysFoster City, Mar: 15 daysFoster City, Apr: 18 daysFoster City, May: 20 daysFoster City, Jun: 23 daysFoster City, Jul: 26 daysFoster City, Aug: 25 daysFoster City, Sep: 26 daysFoster City, Oct: 23 daysFoster City, Nov: 18 daysFoster City, Dec: 15 days
View monthly sunny days as a table
Monthly sunny days (days)
CityJanFebMarAprMayJunJulAugSepOctNovDec
Foster City131315182023262526231815

Compare Foster City with another city

Nearby cities and popular picks. Any two cities can be compared from the home page.

See weather for every covered California city

About this data

Figures are 30 year averages for 1991-2020. Wet days count days with measurable precipitation, calibrated against the wet day counts in NOAA's published climate normals. Sunny days count clear plus partly cloudy days, defined as average cloud cover of 63 percent or less and calibrated against NOAA's published sky cover tables. Snowfall figures are model estimates anchored to NOAA station measurements near each city.

Weather data by Open-Meteo.com (CC BY 4.0). Contains modified Copernicus Climate Change Service information (ERA5, ERA5-Land).