Month-by-month travel weather
San Francisco September weather
San Francisco, United States · September
Sunny afternoons can feel genuinely warm
September often brings some of the warmest-feeling days of the year. Sunny afternoons can feel truly warm.
Evenings still cool down and wind can change comfort quickly—thin layers help.
September averages at a glance
Average low
around 13–14°C
Average high
around 21–25°C
Average precipitation
around 0–10 mm
Rainy days
about 0–2 days
What to wear in September in San Francisco
Actual feel will change with wind and rain, but use the suggestions below to build a comfortable layered outfit.
- • Mix of T-shirts and long sleeves + thin outer layer.
- • Optional sunscreen helps on sunny days.
- • Carry an evening layer if you stay out late.
Travel tips for visiting San Francisco in September
- • Use warm afternoons for longer outdoor routes; layer up later.
- • Coastal/waterfront routes can still feel cooler than inland neighborhoods.
September weather in San Francisco — FAQ
Q. Why can September feel warmer than July?
A. SF often has its warmest-feeling window in early fall rather than midsummer.
Q. Does it rain in September?
A. Usually very little.
Explore San Francisco
These pages are connected so you can compare conditions and decide for yourself.