Weather in San Francisco, California for September 2025
Until now, September 2025 in San Francisco has been significantly cooler than historical averages by -5.1 °F, with average temperature of 16.1 °F.
Expect cooler weather in the next days in San Francisco with the forecast suggesting a temperature of 19.1 °F, lower than the historical average.
In general, the average temperature in San Francisco at the beginning of September is 21.6 °F. As the month progressed, temperatures tended to moderately fall, reaching an average of 19.7 °F by the end of September.
Precipitation in San Francisco during September is a rare event, with an average of fewer than 2 rainy days.
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San Francisco Weather September
Temperatures trend during September in San Francisco
September weather in San Francisco day by day
Date | Weather | Temperatures | Rain | UV | More |
---|---|---|---|---|---|
Sept. 1 | Cloudy | 20° /12° | 0 mm | 4 | |
Sept. 2 | Sunny | 19° /13° | 0 mm | 5 | |
Sept. 3 | Sunny | 22° /13° | 0 mm | 6 | |
Sept. 4 | Sunny | 22° /13° | 0 mm | 6 | |
Sept. 5 | Sunny | 23° /14° | 0 mm | 6 | |
Sept. 6 | Sunny | 23° /13° | 0 mm | 6 | |
Sept. 7 | Sunny | 22° /13° | 0 mm | 6 | |
Sept. 8 | Sunny | 23° /13° | 0 mm | 6 | |
Sept. 9 | Sunny | 21° /13° | 0 mm | 5 | |
Sept. 10 | Partly cloudy | 19° /13° | 0 mm | 5 | |
Sept. 11 | Sunny | 20° /13° | 0.1 mm | 5 | |
Sept. 12 | Sunny | 20° /13° | 0 mm | 5 | |
Sept. 13 | Sunny | 20° /12° | 0 mm | 5 | |
Sept. 14 | Partly cloudy | 19° /15° | 0 mm | 1.7 | |
Sept. 15 | Partly cloudy | 18° /14° | 0 mm | 1.8 | |
Sept. 16 | Mist | 18° /13° | 0 mm | 1.7 | |
Sept. 17 | Sunny | 23° /16° | 0 mm | 1.7 | |
Sept. 18 | Partly cloudy | 18° /15° | 0 mm | 0 | |
Sept. 19 | Sunny | 19° /15° | 0 mm | 5 | |
Sept. 20 | Partly cloudy | 19° /15° | 0 mm | 5 | |
Sept. 21 | Sunny | 19° /15° | 0 mm | 5 | |
Sept. 22 | Sunny | 20° /15° | 0 mm | 5 | |
Sept. 23 | Sunny | 19° /15° | 0 mm | 5 | |
Sept. 24 | Partly cloudy | 18° /15° | 0 mm | 5 | |
Sept. 25 | Sunny | 19° /14° | 0 mm | 5 | |
Sept. 26 | Sunny | 19° /15° | 0 mm | 5 | |
Sept. 27 | Sunny | 20° /15° | 0 mm | 5 | |
Sept. 28 | Sunny | 19° /11° | 0 mm | 5 | |
Sept. 29 | Partly cloudy | 20° /12° | 0 mm | 6 | |
Sept. 30 | Sunny | 23° /12° | 0.5 mm | 6 | |
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San Francisco in September - FAQ
UV exposure in San Francisco during September
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