San Francisco Weather: September
 |
Average Day Temperature: | 66.7°F |
|
Average Night Temperature: | 58.0°F |
|
Sea Water Temperature: | 63.4°F |
|
Number of Sunny Days: | 17 days |
| Sunshine Hours: | 11.8 - 13.0 hours | |
|
Number of Rainy Days: | 0 days |
| Precipitation Totals: | 0.1 in | |
| detailed information | ||
forecast
| San Francisco |
Temperature
| San Francisco |
Air Temperature in September, °F
The highest day temperature in September 2025 was 90°F. The lowest night temperature was 57°F. The average values for day and night temperatures during September were 67.1°F и 60.1°F respectivly.
San Francisco Water Sea Temperature in September, °F
The average sea surface temperature in September 2025 for San Francisco was 66.4°F. The maximum and minimum values were 63.6°F and 68.8°F respectively.
Most of the days in September are sunny but you can also expect cloudy and gloomy days.
Precipitation Totals in September, in
Precipitation total in September for San Francisco is 0.1 in. It makes september the least rainy month of the year.
The average wind speed in September is 7.6 mph. It makes September one of the most windless months of the year for San Francisco.
We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for San Francisco in September is 8.4 hours.
San Francisco on the Weather Map
| Chicago |  |
-2 |
| Hawaii | |
+78 |
| Honolulu | |
+78 |
| Houston | |
+44 |
| Las Vegas |  |
+40 |
| Los Angeles | |
+52 |
| Maui | |
+72 |
| Miami | |
+72 |
| Miami Beach |  |
+80 |
| New York | |
+18 |
| San Diego | |
+54 |
| San Francisco | |
+46 |
| Sarasota | |
+62 |
| Tampa | |
+62 |
| Washington | |
+28 |
| 0300 |  |
46°F | SW 3 mph |
| 0600 |  |
48°F | SW 4 mph |
| 0900 | |
48°F | SW 5 mph |
| 1200 | |
48°F | SW 3 mph |
| 1500 |  |
50°F | SE 2 mph |
| 1800 | |
50°F | E 4 mph |
| 2100 | |
52°F | E 3 mph |
| 0000 | |
52°F | N 2 mph |