San Bruno Weather in September

San Bruno in September averages 23°C (73°F) during the day and 13°C (55°F) at night. Minimal rainfall is typical for this time of year.

Rainfall in San Bruno in September

Typically, about a single day will experience rainfall, with an average of 3.7 mm (0.1 in) for the month. On the rare occasion it rains this month, it usually amounts to very little.

Temperature in San Bruno in September

San Bruno in September is worth a visit. The temperature is excellent, with 23°C (73°F) during the day and 13°C (55°F) at night. This kind of day-to-night contrast is typical for this time of year. With lows of 13°C (55°F), nights are cool. If you're out after dark, an extra layer will keep you comfortable. The cooler air at night is also great for getting a good rest. On average, it is the month with the highest temperature of the year.

Sunshine in San Bruno in September

The city usually sees around 270 hours of sunlight, indicating many sunny days — a great month for sightseeing.

Wind Speed in San Bruno in September

Average wind conditions reach 5 m/s (10 knots) in September. This creates lively weather with fresh winds that make small trees sway noticeably. Remember this is an average: some days are less windy while others have particularly active windy conditions.

Average water temperature in September

The water temperature is 14°C (57°F) — chilly, but perfectly fine for a swim if you're not too sensitive to cold water. A short wetsuit can make longer sessions more comfortable.

If your ideal day consists of dry skies and pleasant temperatures, May, June, July, August, September and October typically offer the best circumstances for San Bruno.

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• January
• February
• March
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• May
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• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our San Bruno's climate page.

San Bruno Temperature in September

Min Temperature 13°C (55°F)  

Max Temperature 23°C (73°F)  

Water Temperature 14°C (57°F) *  

Chance of Rain 3%  

Precipitation 3.7 mm (0.1 in)  

Rainy days a single day  

Humidity 73% *  

Windspeed 5 m/s (10 knots) *  

Sunshine 270 hours *  

Percentage Sunshine 73% *  

* Data from: San Francisco, the United States of America (2 KM, 1 Miles).

What to Wear in San Bruno in September

Comfortable temperatures call for an easy wardrobe in September. Pack summer basics like t-shirts and shorts, but include a light jacket for cooler moments. A pair of comfortable walking shoes is essential. Dry conditions mean you won't need to worry about rain protection. Expect water temperatures of around 14°C (57°F), which is definitely too cold for comfortable swimming. Your luggage space is better used for other items. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.

What To Do in San Bruno in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Cycling

10/10

Walking

10/10

Barbeque

9/10

Camping

10/10

Outdoor sports

10/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our San Bruno's climate page.

More climate data for San Bruno

Temperature Rainfall Sunshine Humidity Wind Speed Water Temp

See the full San Bruno climate overview or explore weather in the United States of America.