‹ San Francisco weather by month
Typical September weather
San Francisco
California · September
70° days
56° nights
rain is rare · 12½ hours of daylight · ocean 65°
What to pack
- Light jacket
What September feels like
September is the month San Franciscans plan around: the fog retreats, the rooftops open, and the bay is as warm as it ever gets. It is also when the hottest days of the year arrive, in a city with almost no air conditioning.
Rain is genuinely rare — most years, September stays dry start to finish.
Can you swim?
The ocean runs about 65° — brisk but swimmable.
The numbers
| Typical high | 70° |
|---|---|
| Typical low | 56° |
| Days with real rain | 0 |
| Total rain | 0.1 in |
| Water temperature | 65° |
| Sunrise / sunset (mid-month) | 6:51 am / 7:17 pm |