Climate and monthly weather forecast
San Bruno, CA

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Weather in January

January, the same as December, in San Bruno, California, is another refreshing winter month, with an average temperature fluctuating between 56.3°F (13.5°C) and 47.8°F (8.8°C). As San Bruno steps into January, the average high-temperature holds at a still moderate 56.3°F (13.5°C), hinting at a minor fluctuation from the prior month. Weather in January »

Weather in February

The last month of the winter, February, is also a moderate month in San Bruno, California, with an average temperature varying between 57.2°F (14°C) and 47.8°F (8.8°C). The arrival of February marks a slight shift to an average high-temperature of a still moderate 57.2°F (14°C) from January's 56.3°F (13.5°C). Weather in February »

Weather in March

March, the first month of the spring in San Bruno, is also a moderate month, with an average temperature ranging between min 48°F (8.9°C) and max 58.5°F (14.7°C). The shift into March uncovers an average high-temperature of a still mild 58.5°F (14.7°C), subtly different from the previous month. Weather in March »

Weather in April

April is a refreshing spring month in San Bruno, California, with an average temperature varying between 60.8°F (16°C) and 49.3°F (9.6°C). April begins with an average high-temperature of a comfortable 60.8°F (16°C), reflecting close similarity to the preceding month. Weather in April »

Weather in May

May, the last month of the spring in San Bruno, is also an enjoyable month, with temperature in the range of an average low of 51.3°F (10.7°C) and an average high of 62.8°F (17.1°C). As April turns into May, the average high-temperatures rest at a still refreshing 62.8°F (17.1°C), showing a minor variation from the prior month. Weather in May »

Weather in June

The first month of the summer, June, is still a comfortable month in San Bruno, California, with an average temperature fluctuating between 67.3°F (19.6°C) and 53.8°F (12.1°C). San Bruno's weather, upon June's arrival, documents an average high-temperature of a still enjoyable 67.3°F (19.6°C), nearly identical to the prior month. Weather in June »

Weather in July

July is a pleasant summer month in San Bruno, California, with an average temperature fluctuating between 68.5°F (20.3°C) and 54.7°F (12.6°C). July's weather displays an average high-temperature of an agreeable 68.5°F (20.3°C), slightly varied from June's 67.3°F (19.6°C). Weather in July »

Weather in August

August, the last month of the summer in San Bruno, is also an agreeable month, with temperature in the range of an average low of 56.3°F (13.5°C) and an average high of 69.1°F (20.6°C). San Bruno's August average high-temperature settles at a still agreeable 69.1°F (20.6°C), showing a near match with the preceding month. Weather in August »

Weather in September

The first month of the autumn, September, is also an agreeable month in San Bruno, California, with an average temperature fluctuating between 69.8°F (21°C) and 56.5°F (13.6°C). September is the warmest month, exhibiting average temperatures of 69.8°F (21°C) at the peak and 56.5°F (13.6°C) at the base. Weather in September »

Weather in October

October, like September, in San Bruno, California, is another refreshing autumn month, with an average temperature varying between 55.6°F (13.1°C) and 66.7°F (19.3°C). In October, San Bruno experiences a minor shift in meteorological conditions with average high-temperatures marked at a comfortable 66.7°F (19.3°C), closely mirroring the climate in September. Weather in October »

Weather in November

The last month of the autumn, November, is another refreshing month in San Bruno, California, with an average temperature varying between 51.8°F (11°C) and 61°F (16.1°C). The arrival of November is marked by a minor reduction in average high-temperature, sliding from a comfortable 66.7°F (19.3°C) in October to a still enjoyable 61°F (16.1°C). Weather in November »

Weather in December

December, the first month of the winter in San Bruno, is still a mild month, with an average temperature fluctuating between 47.7°F (8.7°C) and 55.8°F (13.2°C). San Bruno records the coldest temperatures in December, averaging a high of 55.8°F (13.2°C) and a low of 47.7°F (8.7°C). Weather in December »

Frequently asked questions

How many days does it rain?

In San Bruno, during the entire year, the rain falls for 81.8 days and collects up to 13.46" (342mm) of precipitation.

What is the rainiest month?

February is the month with the most rainfall. Rain falls for 9 days and accumulates 2.72" (69mm) of precipitation.

When is the lowest UV index?

The months with the lowest UV index are February, November and December, with an average maximum UV index of 3.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.

When are the longest days?

June has the longest days of the year, with an average of 14h and 42min of daylight.

When is the highest UV index?

The months with the highest UV index in San Bruno are June through September, with an average maximum UV index of 5.

What is the driest month?

July and August are months with the least rain when the rain falls for 2.2 days and typically aggregates up to 0.04" (1mm) of rain.

What month has the most sunshine in San Bruno?

July has the most sunshine of the year, with an average of 11.8h of sunshine.

What is the most humid month?

With an average relative humidity of 79%, August is the most humid month.

What part of the year is the hottest?

San Bruno's temperature records reveal September as the warmest month, marked by average highs of 69.8°F (21°C) and lows of 56.5°F (13.6°C).

What is the least humid month?

October and November, with an average relative humidity of 71%, are the least humid months.

What month is the coldest?

In San Bruno, December is the month with the lowest recorded average temperatures, measuring a high of 55.8°F (13.2°C) and a low of 47.7°F (8.7°C).

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 36min of daylight.

What is the month with the least sunshine?

The month with the least sunshine is December, with an average of 5.8h of sunshine.

Average temperature
San Bruno, CA

Average temperature - San Bruno, CA

The warmest month (with the highest average high temperature) is September (69.8°F).
The month with the lowest average high temperature is December (55.8°F).

The month with the highest average low temperature is September (56.5°F).
The coldest month (with the lowest average low temperature) is December (47.7°F).

Average pressure
San Bruno, CA

Average pressure - San Bruno, CA

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).

Average wind speed
San Bruno, CA

Average wind speed - San Bruno, CA

The windiest month (with the highest average wind speed) is April (8.5mph).
The calmest months (with the lowest average wind speed) are August and September (6.3mph).

Average humidity
San Bruno, CA

Average humidity - San Bruno, CA

The month with the highest relative humidity is August (79%).
The months with the lowest relative humidity are October and November (71%).

Average rainfall
San Bruno, CA

Average rainfall - San Bruno, CA

The wettest month (with the highest rainfall) is February (2.72").
The driest months (with the least rainfall) are July and August (0.04").

Average rainfall days
San Bruno, CA

Average rainfall days - San Bruno, CA

The month with the highest number of rainy days is March (13.3 days).
The months with the least rainy days are July and August (2.2 days).

Average daylight / Average sunshine
San Bruno, CA

Average daylight / Average sunshine - San Bruno, CA

The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).

The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).

Average sunshine days
San Bruno, CA

Average sunshine days - San Bruno, CA

The month with the most sunshine days is July (27.3 days).
The month with the least sunshine days is March (16.3 days).

Average UV index
San Bruno, CA

Average UV index - San Bruno, CA

The months with the highest UV index are June, July, August and September (UV index 5).
The months with the lowest UV index are February, November and December (UV index 3).

Average visibility
San Bruno, CA

Average visibility - San Bruno, CA

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

San Bruno, California, USA

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