San Bruno (CA) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit San Bruno.
Climate overview of San Bruno
San Bruno, California, United States of America, has a moderate seasonal temperature range, with September reaching 23°C (73°F) and December cooling to 14°C (57°F).
With around 481 mm (19 in) of annual rainfall, San Bruno has a fairly dry climate. However, it has a distinct dry season from May to October. The wettest month is December, while July sees the least rain. The sunniest month is May, with 10.8 hours of sunshine per day on average.
San Bruno Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in San Bruno - and find the best time to visit.
Monthly Temperature in San Bruno
The climate in San Bruno experiences moderate temperature changes, with mild shifts between seasons. Average daytime temperatures reach a comfortable 23°C (73°F) in September. In December, the coolest month of the year, temperatures drop to a moderate 14°C (57°F).
At night, temperatures range from around 14°C (57°F) in September to 7°C (45°F) in December.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in San Bruno
San Bruno tends toward drier weather patterns, receiving approximately 481 mm (19 in) of rain per year. San Bruno can be quite wet during December, receiving approximately 113 mm (4.4 in) of precipitation over 13 rainy days.
In contrast, during the driest month (July), you will experience much drier conditions, with 0.6 mm (0.02 in) of precipitation spread across a single rainy day. For more details, please visit our San Bruno Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in San Bruno
San Bruno can be enjoyed more throughout the sunniest month of May under a blue sky, with approximately 10.8 hours of sunshine daily. In contrast, the city experiences much darker days in December, with only 5.3 hours of sunlight per day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Water Temperature in San Bruno
The mean water temperature over the year ranges from 12°C (54°F) in January to 14°C (57°F) in June.
Water temperature over the year
Humidity in San Bruno by Month
The relative humidity is high throughout the year in San Bruno.
The city experiences its highest humidity in January, reaching 80%. In June, the humidity drops to its lowest level at 71%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Wind Speed in San Bruno
The mean wind speed over the year ranges from 3 m/s (6 knots) in January, November and December to 7 m/s (14 knots) in June and July. What does this mean?
The mean monthly wind speed over the year (meters per second)
Best Time to Visit San Bruno
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: May, June, July, August, September and October
- Warmest weather: July, August, September and October
- Most sunshine: April, May, June and July
- Fewer rainy days: May, June, July, August and September
- Wettest months: January, February, March, April and December, when rainfall is highest.
- Seasonal pattern: A distinct dry season from May to October
Frequently asked questions about the climate in San Bruno
What is the best time to visit San Bruno?
May, June, July, August, September and October typically offer the most optimal weather in San Bruno. In contrast, December tends to have less optimal conditions. San Bruno has a distinct dry season from May to October.
What temperatures can I expect in San Bruno?
Daytime highs range from 14°C (57°F) in December to 23°C (73°F) in September. Nighttime lows range from 7°C (45°F) to 14°C (57°F).
How much rain does San Bruno get?
Annual rainfall is around 481 mm (19 in). December is the wettest month with 113 mm (4.4 in), while July is the driest with 0.6 mm (0.02 in).
How sunny is San Bruno?
San Bruno receives around 3,058 hours of sunshine per year. May is the sunniest month with 324 hours, while December is the cloudiest with just 160 hours. Overall, San Bruno enjoys abundant sunshine.
San Bruno 3-Day Forecast
San Bruno (CA) 3-Day Forecast
San Bruno on the map
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