San Francisco weather in September (California, United States of America)

How is the weather in San Francisco in September? This guide provides all the weather details you need.

In San Francisco, September is characterized by high temperatures and almost no rainfall. Anticipate daytime temperatures around 73°F (show in °C), while night temperatures can drop to 56°F. On average, it is the month with the highest temperature of the year.

San Francisco in September usually receives almost no rainfall, averaging around 0.1 inches (show in mm) for the month. When we look at the climate data from the last 30 years, we can expect around 1 day of rain.

The city usually sees around 270 hours of sunlight, indicating many sunny days.

If you're inclined towards comfortable temperatures and drier conditions, September is a prime time to visit San Francisco. May, June, July, August, September and October typically offer the best weather. While December tends to showcase less optimal conditions.

For an in-depth look at the yearly weather and climate conditions, visit our specialized San Francisco climate page with graphs.


San Francisco, monthly averages in September

Show in Celsius
Min Temperature 55.9°F  
Max Temperature 73.2°F  
Water Temperature 57°F  
Chance of Rain 3%  
Precipitation 0.1 inches  
Rainy days 1 day  
Humidity 73%  
Windspeed 11 mph  
Sunshine 270 hours  
Percentage Sunshine 73%  

Where to go in the United States of America in September

Find out more about the weather in the United States of America in September and which places have the best weather conditions in this month.

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Legend perfect weather pleasant tolerable unpleasant poor
Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20-29ºC / 68-84ºF and not too much precipitation (less than 90mm / 3.5inches a month).

So, what should you wear in San Francisco in September?

​ 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 57°F 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 in September.

Outdoor sports

Interested in more climate information?

Weather and Climate 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 climate conditions. Find out where to go with our weather planner.