San Francisco Weather in September
September in San Francisco brings very high temperatures around 31°C (88°F) during the day, dropping to 26°C (79°F) at night, with the most rainfall of the year.
Rainfall in San Francisco in September
Expect the heaviest rain of the year this month, often arriving in intense bursts. A poncho is essential for keeping dry. Analyzing past climate data, one can expect approximately 18 days of rain, averaging 254 mm (10 in). This month brings frequent, heavy showers. Both the number of wet days and the rainfall totals are on the high side.
Temperature in San Francisco in September
Temperatures in San Francisco in September top out at 31°C (88°F) and drop to 26°C (79°F) overnight. Mornings and evenings are often more comfortable than the peak afternoon hours. With overnight lows of 26°C (79°F), nights stay very warm. Air conditioning makes a real difference if you're sensitive to heat. A cold shower before bed can also help you get to sleep more comfortably.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.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Mexico, check out our San Francisco's climate page.
San Francisco Temperature in September
Min Temperature
26°C (79°F)
Max Temperature
31°C (88°F)
Chance of Rain
59%
Precipitation
254 mm (10 in)
Rainy days
18 days
Humidity
70% *
Best Places in Mexico in September
Find out more about the weather in Mexico and which places have the best travel conditions in this month. See all of Mexico in September →
perfect weather
pleasant
tolerable
unpleasant
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What to Wear in San Francisco in September
Warm weather calls for comfortable, breathable clothing in September. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). Also bring a poncho, it will rain a lot! Waterproof everything you can.What To Do in San Francisco in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Mexico, check out our San Francisco's climate page.
See the full San Francisco climate overview or explore weather in Mexico.
