San Francisco in September
5.8out of 10
Possible, with caveats
Hot: daytime highs around 30°C. Very wet: about 26 rainy days.
30°CAvg high
21°CAvg low
26Rainy days (316 mm)
12:04 hDaylight
05:45Sunrise · 17:49 Sunset
Why this score
- Hot: daytime highs around 30°C
- Very wet: about 26 rainy days
What to wear and pack
- Light, breathable clothing
- Shorts or a light skirt
- Rain jacket or compact umbrella
- Sunscreen, sunglasses and a hat
How reliable is the forecast?
Rainfall in September is fairly consistent from year to year (2.7 days). Averages cover 30 years (1991–2020). Individual days can differ a lot.
Year at a glance
Weather by month
| Month | Avg high | Avg low | Rainfall | Rainy days | Humidity | Sunshine | Score |
|---|---|---|---|---|---|---|---|
| January | 32°C | 19°C | 2 mm | 1 | – | – | 8.2 |
| February | 33°C | 20°C | 2 mm | 1 | – | – | 7.8 |
| March | 34°C | 21°C | 14 mm | 3 | – | – | 7.3 |
| April | 34°C | 22°C | 67 mm | 11 | – | – | 6.3 |
| May | 32°C | 22°C | 281 mm | 23 | – | – | 5.3 |
| June | 31°C | 21°C | 265 mm | 24 | – | – | 5.7 |
| July | 32°C | 21°C | 145 mm | 17 | – | – | 5.6 |
| August | 32°C | 22°C | 212 mm | 22 | – | – | 5.3 |
| September | 30°C | 21°C | 316 mm | 26 | – | – | 5.8 |
| October | 29°C | 21°C | 290 mm | 24 | – | – | 6.0 |
| November | 30°C | 20°C | 56 mm | 8 | – | – | 7.8 |
| December | 31°C | 19°C | 5 mm | 1 | – | – | 8.3 |
Frequently asked questions
How hot is San Francisco in September?
Daytime highs average 30°C and nights about 21°C.
When is the best time to visit San Francisco?
The best months are December, January, February, November.