San Francisco Weather in September

September in San Francisco typically sees daytime highs of 23°C (73°F) and nighttime lows of 13°C (55°F). September falls within the rainy season, so heavy rainfall is to be expected.

Rainfall in San Francisco in September

As part of the rainy season, San Francisco sees around 15 days of rain in September, with an average of 283 mm (11 in). Rainy season showers here are typically intense, often clearing quickly but coming down hard while they last.

Temperature in San Francisco in September

In September, San Francisco sees high temperatures, with highs of 23°C (73°F). Nights drop to around 13°C (55°F). Conditions stay fairly consistent through the month, making it easier to plan what to wear. Nights cool down to 13°C (55°F), so a light jacket or extra layer is useful once the sun goes down. On the plus side, the cooler nights make for comfortable sleeping conditions.

Sunshine in San Francisco in September

The area enjoys a balanced 111 hours of sunlight, ensuring it's neither too rainy nor too sunny.

If you prefer dry days with pleasant temperatures, September may not be the ideal month to visit San Francisco. Our weather planner can help you explore destinations with more pleasant weather conditions.