San Francisco weather in September (California, United States of America)
How's the weather trend in San Francisco as September approaches? Curious if the timing is right for your trip? Our page offers an in-depth look at the monthly weather conditions.
Temperatures
Monthly weather patterns in San Francisco during September are typically perfect, bringing high temperatures and almost no rainfall. Anticipate monthly maximum daytime temperatures around 23°C, while night temperatures can drop to 13°C. On average, it is the month with the highest temperature of the year.
Precipitation
San Francisco in September usually receives almost no rainfall, averaging around 3.4 mm for the month. Expect around a single day of rain based on historical data.
Average sunshine
With approximately 270 hours of sunshine, the days are filled with clear skies. It makes it a perfect month for being outside.
Average windspeed
Average wind conditions reach 5 m/s in September. This creates lively weather with fresh winds that make small trees sway noticeably. Remember this is an average: some days are less windy while others have particularly active windy conditions.
Average water temperature in September
The water temperature is 14°C, still a bit chilly for most swimmers but manageable for those who don't mind cooler conditions. You might find yourself getting used to it after a few minutes.If you're a fan of comfortable temperatures and drier conditions, September is a great time to visit.
Select a Month of Interest
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our San Francisco's climate page.
San Francisco, monthly averages in September
Where to go in the United States of America in September
Find out more about the weather in the United States of America and which places have the best travel conditions in this month.





Select a Month of Interest
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our San Francisco's climate page.
So, what should you wear in this month?
For visitors traveling to San Francisco, we recommend wearing layers. So maybe a skirt, t-shirt, shorts for during the day and jeans and a warm jacket for some days and evenings. With a water temperature of around 14°C there is no need to bring your swimwear.What To Do
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Interested in more climate information?
This site provides you with all the information you need about the climate in San Francisco.
Our site offers climate and forecast data for every country in the world. Are you going to the United States of America? On this website you can find historical weather averages for many cities in the United States of America. Not sure yet where to go? We now have a tool which recommends destinations that suit your ideal travel conditions. Find out where to go with our weather planner.