San Francisco weather in August
Temperature, sea and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Excellent
Best time to visit: April – October
What is the weather like in San Francisco in August?
In August, San Francisco is warm: daytime highs average 22 °C, and nights cool down to about 13 °C. The sea averages 14.5 °C – swimming is only for the hardy. With around 11 hours of sunshine a day, there is plenty of sun. It hardly ever rains. All in all, August is an excellent month for a holiday in San Francisco.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 100 | 100 | 100 |
| Day | 22° | 22° | 23° |
| Night | 13° | 13° | 13° |
| Sea | 14° | 15° | 15° |
| Sun | 11 h | 11 h | 10 h |
| Rain days | 0 | 0 | 1 |
More details for August
- Daylight
- 13 h 40 min06:25 – 20:05
- UV index
- 9 · very highclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or more
- Wind
- 17 km/haverage daily peak
- Cloud cover
- 39 %on average
- Hot days
- 1 day30 °C or more
- Time zone
- UTC−7America/Los_Angeles
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %100 %
- Few rainy daysweight 30 %100 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in August
- Sunscreen
- Sunglasses & sun hat
- A jumper for the evenings
San Francisco in August: quick answers
Is San Francisco hot in August?
Warm rather than hot: in August, daytime highs in San Francisco average 22 °C and nights cool to about 13 °C.
Can you swim in San Francisco in August?
Only if you don't mind cold water: in August the sea averages just 14.5 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in San Francisco in August?
It hardly ever rains.
San Francisco month by month
The whole year in San FranciscoAll destinations: USAWhere to go in August
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, GeoNames (CC BY 4.0)