Foster City (CA) Weather and Climate: A Comprehensive Guide
The weather in Foster City sees moderate temperature fluctuations over the course of a year.
Temperatures can be warm at the high end
to roughly mild at the low end.
It maintains relatively low levels of precipitation throughout the seasons.
Now, let’s explore all the climate details to give you a full picture.
Average maximum day and minimum night temperature
The climate in Foster City experiences moderate temperature changes, with mild shifts between seasons. On average, daytime temperatures range from a comfortable 24°C in September to a moderate 14°C in January.
Nighttime temperatures can drop, with average lows reaching 6°C in January. Check out our detailed temperature page for more information.Temperature ranges by month
Precipitation and rainy days
Foster City tends toward drier weather patterns, receiving approximately 401 mm of rain per year. The seasons in Foster City, bring significant changes in precipitation. The wettest month, December, receives moderate rainfall, with an average of 96 mm of precipitation. This rainfall is distributed across 12 rainy days. In contrast, the driest month, July, experiences much less rainfall, totaling 0 mm over 0 rainy days. These distinct seasonal differences provide diverse experiences throughout the year. For more details, please visit our Foster City Precipitation page.The mean monthly precipitation over the year, including rain, hail and snow
The average number of days each month with precipitation
Sunshine over the year
In Foster City, summer days are longer and more sunny, with daily sunshine hours peaking at 10.8 hours in May. As the darker season arrives, the brightness of the sun becomes less. December sees a soft sun for only 5.3 hours per average day. Visit our detailed sunshine hours page for more information.Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Average water temperature
The mean water temperature over the year ranges from 12°C in January to 14°C in June.
Water temperature over the year
Average humidity
The relative humidity is high throughout the year in Foster City.
The city experiences its highest humidity in January, reaching 80%. In June, the humidity drops to its lowest level at 71%. Explore our detailed page on humidity levels for further details.
Relative humidity over the year
Average wind speed
The mean wind speed over the year ranges from 3 m/s in January, November and December to 7 m/s in June and July.
The mean monthly wind speed over the year (meters per second)
broken clouds and no rain broken clouds and slight rain broken clouds and rainForecast for Foster City (CA)
3 m/s
4 m/s
5 m/s
The best time of year to visit Foster City in the United States of America
During the months of May, June, July, August, September and October you are most likely to experience good weather with pleasant average temperatures that fall between 20°C and 26°C.Other facts from our historical weather data:
Yes, the months of May, June, July, August and September are very dry.
September has an average maximum temperature of 24°C and is the warmest month of the year.
The coldest month is December with an average maximum temperature of 14°C.
December tops the wettest month list with 96 mm of rainfall.
July is the driest month with 0 mm of precipitation.
May is the sunniest month with an average of 324 hours of sunshine.
No idea where to travel to this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.
