01Weather
San Francisco weather in September
Afternoons in September average 24.2 °C (76 °F) and nights cool to 14.1 °C (57 °F). The month brings about 3 mm (0.1 in) of rain spread over roughly 0 days. Compared with August it is 0.8 °C warmer; October is 1.2 °C cooler again.
What the averages hide
| In a typical September | Value | What it means |
|---|---|---|
| Warm afternoons (90th percentile) | 31 °C / 87 °F | one day in ten is at least this warm |
| Cool afternoons (10th percentile) | 20 °C / 68 °F | one day in ten stays below this |
| Cold nights (10th percentile) | 11 °C / 52 °F | one night in ten is colder than this |
| Days above 30 °C (86 °F) | 3.4 | per month, average 2016–2025 |
| Nights at or below 0 °C (32 °F) | 0.0 | frost mornings per month |
| Chance of rain on any given day | 2 % | at least 1 mm |
| Hottest / coldest September day 2016–2025 | 40.0 °C / 8.3 °C | extremes in the ten-year record |
02Daylight
Sunrise, sunset and the length of the day
| Date | Sunrise | Sunset | Daylight |
|---|---|---|---|
| 1 September | 06:39 | 19:39 | 13.0 h |
| 15 September | 06:51 | 19:18 | 12.4 h |
| 30 September | 07:04 | 18:54 | 11.8 h |
Daylight shrinks by about 72 minutes over the month. Times are local (America/Los_Angeles).
03Crowds
How busy San Francisco is in September
very busy The main sights are very busy in September. What drives it:
- warmest month
- Dreamforce
- Folsom Street Fair
- Labor Day
04Public holidays
Public holidays in September 2027
| Date | Holiday |
|---|---|
| 6 Sep 2027 | Labour Day |
On public holidays many shops close and museums run on Sunday hours; check opening times for the day before and after as well.
05Events
What's on in San Francisco in September
Every year in September
| Event | When | Type |
|---|---|---|
| Dreamforce | September, Moscone Center | fair |
| Folsom Street Fair | last Sunday of September | festival |
07Packing
What to pack for San Francisco in September
- layers: t-shirt plus a light jacket for evenings
- comfortable walking shoes
- something for heat: 3 days a month pass 30 °C on average
08Editor's notes
What the numbers don't tell you
September is the warmest month and the best, with the fog lifting, clear days around 22 °C and the city at its most photogenic. Dreamforce can book out downtown hotels for a week in the second half, and the Folsom Street Fair closes the month. Labor Day weekend at the start marks the end of beach season elsewhere but the start of it here. Rain is rare, about one day.
The Sausalito Art Festival over Labor Day weekend and the Opera's opening night fill the calendar. Alcatraz needs two weeks' notice. Ocean Beach is warm enough to sit on, if not to swim. Hotel rates are high outside Dreamforce but justified. Daylight drops from thirteen to twelve hours. For Fleet Week, Hardly Strictly and Halloween, see October.
09Compare
San Francisco month by month
| Month | High | Low | Rain days | Sun h | Crowds | Verdict |
|---|---|---|---|---|---|---|
| January | 15 °C | 7 °C | 7 | – | quiet | Good |
| February | 17 °C | 7 °C | 7 | – | quiet | Good |
| March | 17 °C | 8 °C | 8 | – | moderate | Excellent |
| April | 19 °C | 10 °C | 5 | – | moderate | Excellent |
| May | 20 °C | 12 °C | 2 | – | busy | Excellent |
| June | 22 °C | 13 °C | 0 | – | very busy | Good |
| July | 22 °C | 14 °C | 0 | – | very busy | Good |
| August | 23 °C | 15 °C | 0 | – | very busy | Good |
| September | 24 °C | 14 °C | 0 | – | very busy | Good |
| October | 23 °C | 11 °C | 2 | – | busy | Excellent |
| November | 18 °C | 8 °C | 5 | – | moderate | Excellent |
| December | 15 °C | 6 °C | 8 | – | moderate | Good |
Not sure about September? See the best time to visit San Francisco.
10Elsewhere
September in nearby cities
| City | High | Rain days |
|---|---|---|
| Los Angeles in September | 26 °C | 0 |
| Las Vegas in September | 35 °C | 0 |
| Vancouver in September | 20 °C | 9 |
| Toronto in September | 23 °C | 8 |
| Cancún in September | 32 °C | – |
| Orlando in September | 32 °C | 9 |
11FAQ
San Francisco in September: your questions
Is September a good time to visit San Francisco?
September is a good month to visit San Francisco. Daytime highs average 24 °C (76 °F), rain falls on about 0 days, and hotel arrivals run above the yearly average, so the main sights are very busy.
What is the weather like in San Francisco in September?
Expect warm days around 24 °C (76 °F) and nights near 14 °C (57 °F). One September in ten brings afternoons above 31 °C, and one in ten stays below 20 °C.
Does it rain a lot in San Francisco in September?
September brings about 3 mm (0.1 in) of rain over roughly 0 days, which is dry by San Francisco standards. On any given day the chance of at least 1 mm of rain is 2 percent.
What should I wear in San Francisco in September?
Pack layers: t-shirt plus a light jacket for evenings, comfortable walking shoes, something for heat: 3 days a month pass 30 °C on average.
Is San Francisco crowded in September?
The main sights are very busy in September. Main drivers: warmest month; Dreamforce; Folsom Street Fair.
What time does it get dark in San Francisco in September?
Around the middle of September the sun sets at about 19:18 and rises at 06:51, giving 12.4 hours of daylight.