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Contents
- The climate of San Francisco
- The best time to visit San Francisco
- The worst time to visit San Francisco
- Spring weather in San Francisco
- Summer weather in San Francisco
- Autumn weather in San Francisco
- Winter weather in San Francisco
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average sea temperature
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
A beautiful dusk view of the Golden Gate Bridge in San Francisco, California
The climate of San Francisco
San Francisco, located in California, USA, falls within Köppen's Csb-predominate climate zone. This Mediterranean Zone is characterized by warm summers, which contribute to San Francisco's renowned mild temperate maritime climate. The year-round weather conditions exhibit significant homogeneity, with only slight fluctuations in temperature, humidity, and pressure.
Throughout the year, San Francisco experiences fairly consistent temperatures, with monthly averages hovering between 45.9°F (7.7°C) and 72.5°F (22.5°C). Relative humidity remains quite steady, oscillating around the 70% mark all year round, contributing to a humid and pleasant climate. The rainfall distribution also complements the overall weather, with rainfall peaking in January and February at around 1.38" (35mm) but dipping to as low as 0.08" (2mm) between June and September.
One of the distinguishing features of San Francisco's climate is the discrepancy in the monthly sunshine hours. Despite the city's often cloudy weather, there is a distinct increase in sunlight during the summer months, with average daily sunshine hours reaching up to 14.8 in June. This pattern of increased sunlight is followed by a gradual decrease moving into the autumn and winter seasons.
Throughout the year, San Francisco experiences fairly consistent temperatures, with monthly averages hovering between 45.9°F (7.7°C) and 72.5°F (22.5°C). Relative humidity remains quite steady, oscillating around the 70% mark all year round, contributing to a humid and pleasant climate. The rainfall distribution also complements the overall weather, with rainfall peaking in January and February at around 1.38" (35mm) but dipping to as low as 0.08" (2mm) between June and September.
One of the distinguishing features of San Francisco's climate is the discrepancy in the monthly sunshine hours. Despite the city's often cloudy weather, there is a distinct increase in sunlight during the summer months, with average daily sunshine hours reaching up to 14.8 in June. This pattern of increased sunlight is followed by a gradual decrease moving into the autumn and winter seasons.
The best time to visit San Francisco
Visitors seeking the best of San Francisco's weather should consider planning their trip between June and October. During these months, the city enjoys daylight hours extending between 12.4 hours to 14.8 hours, allowing ample time to explore the famous city landmarks. With monthly average temperatures peaking at a comfortable 72.5°F (22.5°C) in August, sun seekers can find this period favorable for outdoor activities. Moreover, the lowest rainfall during these months, averaging just 0.08" (2mm), provides a dry spell rarely interrupted by showers.
The worst time to visit San Francisco
While San Francisco doesn’t have a definitive ‘worst’ time to visit, those not fond of cooler temperatures and increased rain should avoid the months from November to March. The temperature during these months falls to a low of 45.9°F (7.7°C) and the city witnesses increased rainfall, particularly in February with precipitation reaching 1.38" (35mm). The reduced daylight hours, particularly from December to February, where sunshine falls to around 9.9 hours to 10.1 hours respectively, further limit the time for exploration and outdoor activities.
Spring weather in San Francisco
In San Francisco, the spring season heralds mild weather conditions with an upswing in temperatures and a noticeable decrease in rainfall. Spanning March through May, the city experiences average high temperatures ranging from 60.1°F (15.6°C) to 65.7°F (18.7°C) and lows dawdling between 46.9°F (8.3°C) and 50.5°F (10.3°C). Rainfall significantly decreases during this period, falling from 0.87" (22mm) in March to 0.35" (9mm) by May. The increasing daylight, peaking at 14.2 hours in May, proves opportune for sightseeing and outdoor attractions.
Summer weather in San Francisco
Summers in San Francisco are characterized by warm, dry conditions with longer daylight hours. From June to August, high temperatures rise to a peak of 72.5°F (22.5°C), while the lows maintain a comfortable average between 53.8°F (12.1°C) and 56.3°F (13.5°C). Rainfall is minimal during this season, hovering around a meager 0.08" (2mm) per month. Hours of daylight extend up to 14.8 hours in June offering ample sunshine albeit partially veiled by the city’s signature summer fog.
Autumn weather in San Francisco
Autumn in San Francisco, spanning September to November, features slightly cooler temperatures with increased rainfall towards November. The highs start to drop from 73.2°F (22.9°C) in September to a cooler 61.7°F (16.5°C) by November. Lows follow a similar trajectory, dropping from 56.7°F (13.7°C) to 50°F (10°C). Rainfall begins to pick up from a minimal 0.08" (2mm) in September to 0.83" (21mm) by November. Sunlight decreases, ranging from 12.4 hours in September to 10.1 hours by November.
Winter weather in San Francisco
Winter in San Francisco brings cooler temperatures and increased rainfall. Stretching from December to February, this season sees average high temperatures between 55.8°F (13.2°C) to 57.9°F (14.4°C) and lows hovering around 45.9°F (7.7°C) to 46.2°F (7.9°C). While the rainfall peaks at 1.02" (26mm) in December and continues to be considerable till February, it’s often punctuated with bright sunlight, albeit for shorter durations with daily averages hovering between 9.6 hours to 10.8 hours. Despite the cooler weather, winter in San Francisco remains relatively mild compared to most parts of the USA.
Weather in January
The San Francisco winter persists into January, with grey skies often casting over the city. Compared to December, January receives slightly less rain but this month retains the highest average rainfall of the year at 1.02in. Fog often blankets the city, reducing visibility and creating a mystical atmosphere. Weather in January »
Weather in February
San Francisco's February weather is slightly milder compared to January, with warmer days but few signs of spring yet. A noticeable change comes in the form of reduced average rainfall and lower humidity levels, creating a drier environment. Weather in February »
Weather in March
The first signs of spring appear in March, as San Francisco experiences a gradual increase in temperatures. While March breaks away from February's cooler temperatures, it retains an increased rainfall, registering 0.87in of precipitation compared between these two months. Weather in March »
Weather in April
April in San Francisco is characterized by drying conditions and warming trends. Compared to the month of March, rainfall in April reduces significantly to 0.28in, marking the transition from spring to early summer. The city dazzles under the April sun as temperatures continue to rise and days grow longer. Weather in April »
Weather in May
The mild and sunny days of May in San Francisco offer perfect weather for outdoor activities. This month, compared to April, witnesses an increase in temperature, with May’s lowest temperature hovering around 50.5°F (10.3°C). Pleasant marine breezes sweep through the city, offering respite from the increasing heat. Weather in May »
Weather in June
June embraces summer in San Francisco, with longer days and shorter nights. June sees a considerable jump in temperatures from May, resulting in more outdoor activity around the city. The summer solstice normally falls within this month, leading to the longest day of the year. Weather in June »
Weather in July
July holds the title as San Francisco's warmest month of the year. However, average temperatures remain quite mild, maxing out at 72.1°F (22.3°C). Despite the prevailing summer-like conditions, San Francisco's July is characterized by cool, windy evenings. Weather in July »
Weather in August
August carries forward the city's quintessential cool and mild summer. This month sees only a marginal increase in temperature from July, hitting a tepid peak of 72.5°F (22.5°C). Suns set late, allowing long, comfortable evenings for alfresco dining or evening strolls. Weather in August »
Weather in September
San Francisco takes on a lovely hue in September as summer begins to make way for fall. This month marks a transition from the mild temperatures of August to slightly cooler ones, with temperatures turning a bit nippy, especially after the sun goes down. Weather in September »
Weather in October
October in San Francisco brings a crispness to the air, as summer slowly slips away. The month ushers in cooler temperatures from September’s conditions, making it a perfect time for sightseeing and outdoor explorations. October is known for its bright, clear days and stunningly vibrant sunsets. Weather in October »
Weather in November
San Francisco's November represents the gateway into early winter. The mild and sunny days of October give way to chillier weather, yet compared to other parts of the United States, November in San Francisco remains fairly mild. Weather in November »
Weather in December
With the arrival of December, San Francisco plunges into winter. Lower temperatures from November's relatively mild condition characterize this month. Despite the winter season, San Francisco's winter is typically milder than much of the United States, with temperatures rarely dropping to freezing point. Weather in December »
Updated: Feb 9, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How much does it rain in San Francisco?
Throughout the year, in San Francisco, California, there are 58.6 rainfall days, and 6.46" (164mm) of precipitation is accumulated.
What are the months with the lowest UV index in San Francisco?
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index in San Francisco, California.
What is the wettest month in San Francisco?
The month with the most rainfall in San Francisco, California, is February, when the rain falls for 6 days and typically aggregates up to 1.38" (35mm) of precipitation.
What is the most humid month in San Francisco?
March is the most humid month in San Francisco, with an average relative humidity of 76%.
When is Daylight Saving Time (DST) in San Francisco?
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.
What are the months with the coldest ocean in San Francisco?
April through June, with an average ocean temperature of 53.1°F (11.7°C), are months with the coldest seawater in San Francisco.
What are the months with the highest UV index in San Francisco?
April, June through September, with an average maximum UV index of 5, are months with the highest UV index in San Francisco, California.
When are the longest days in San Francisco?
The month with the longest days in San Francisco, California, is June, with an average of 14h and 42min of daylight.
What is the driest month in San Francisco?
The months with the least rainfall in San Francisco are July through September Rain falls for 2.3 days and accumulates 0.08" (2mm) of rain.
What month has the most sunshine in San Francisco?
July has the most sunshine of the year in San Francisco, with an average of 11.8h of sunshine.
What is the hottest time of year in San Francisco?
San Francisco notes the warmest temperatures in September, with a average high of 73.2°F (22.9°C) and a low of 56.7°F (13.7°C).
What month is the ocean warmest in San Francisco?
The month with the warmest seawater is September, with an average ocean temperature of 57.4°F (14.1°C).
What is the least humid month in San Francisco?
With an average relative humidity of 67%, October is the least humid month.
What month is the coldest in San Francisco?
With average high and low temperatures of 55.8°F (13.2°C) and 45.9°F (7.7°C) respectively, December is San Francisco's coldest month.
What is the month with the shortest days in San Francisco?
The month with the shortest days in San Francisco, California, is December, with an average of 9h and 36min of daylight.
What is the month with the least sunshine in San Francisco?
The month with the least sunshine in San Francisco is December, with an average of 5.8h of sunshine.
Average temperature
San Francisco, CA
The warmest month (with the highest average high temperature) is September (73.2°F).
The month with the lowest average high temperature is December (55.8°F).
The month with the highest average low temperature is September (56.7°F).
The coldest months (with the lowest average low temperature) are January and December (45.9°F).
Average pressure
San Francisco, CA
- Average pressure in January:
30.13"Hg - Average pressure in February:
30.08"Hg - Average pressure in March:
30.07"Hg - Average pressure in April:
30.03"Hg - Average pressure in May:
29.98"Hg - Average pressure in June:
29.92"Hg
- Average pressure in July:
29.93"Hg - Average pressure in August:
29.92"Hg - Average pressure in September:
29.92"Hg - Average pressure in October:
29.98"Hg - Average pressure in November:
30.07"Hg - Average pressure in December:
30.11"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed
San Francisco, CA
- Average wind speed in January:
5.8mph - Average wind speed in February:
6.8mph - Average wind speed in March:
7.1mph - Average wind speed in April:
7.5mph - Average wind speed in May:
7.6mph - Average wind speed in June:
7.2mph
- Average wind speed in July:
6.5mph - Average wind speed in August:
6.2mph - Average wind speed in September:
5.8mph - Average wind speed in October:
5.6mph - Average wind speed in November:
5.5mph - Average wind speed in December:
6.3mph
The windiest month (with the highest average wind speed) is May (7.6mph).
The calmest month (with the lowest average wind speed) is November (5.5mph).
Average humidity
San Francisco, CA
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is October (67%).
Average rainfall
San Francisco, CA
- Average rainfall in January:
1.02" - Average rainfall in February:
1.38" - Average rainfall in March:
0.87" - Average rainfall in April:
0.28" - Average rainfall in May:
0.35" - Average rainfall in June:
0.12"
- Average rainfall in July:
0.08" - Average rainfall in August:
0.08" - Average rainfall in September:
0.08" - Average rainfall in October:
0.35" - Average rainfall in November:
0.83" - Average rainfall in December:
1.02"
The wettest month (with the highest rainfall) is February (1.38").
The driest months (with the least rainfall) are July, August and September (0.08").
Average rainfall days
San Francisco, CA
- Average rainfall days in January:
8.2 days - Average rainfall days in February:
6 days - Average rainfall days in March:
9.3 days - Average rainfall days in April:
4.8 days - Average rainfall days in May:
4 days - Average rainfall days in June:
1.9 days
- Average rainfall days in July:
2.3 days - Average rainfall days in August:
2.7 days - Average rainfall days in September:
2.5 days - Average rainfall days in October:
3.5 days - Average rainfall days in November:
5 days - Average rainfall days in December:
8.4 days
The month with the highest number of rainy days is March (9.3 days).
The month with the least rainy days is June (1.9 days).
Average sea temperature
San Francisco, CA
The best month for swimming (with the highest average sea temperature) is September (57.3°F).
The coldest months (with the lowest average sea temperature) are April and June (53°F).
Average daylight / Average sunshine
San Francisco, CA
- Average daylight in January:
9h and 5min - Average daylight in February:
10h and 5min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 1min - Average daylight in May:
14h and 1min - Average daylight in June:
14h and 4min
- Average daylight in July:
14h and 3min - Average daylight in August:
13h and 4min - Average daylight in September:
12h and 2min - Average daylight in October:
11h and 1min - Average daylight in November:
10h and 1min - Average daylight in December:
9h and 4min
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).
- Average sunshine in January:
6h and 1min - Average sunshine in February:
6h and 1min - Average sunshine in March:
7h and 5min - Average sunshine in April:
10h and 2min - Average sunshine in May:
10h and 4min - Average sunshine in June:
11h and 4min
- Average sunshine in July:
11h and 5min - Average sunshine in August:
11h and 4min - Average sunshine in September:
10h and 5min - Average sunshine in October:
7h and 0min - Average sunshine in November:
6h and 4min - Average sunshine in December:
5h and 5min
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 Francisco, CA
- Average sunshine days in January:
22 days - Average sunshine days in February:
21.3 days - Average sunshine days in March:
20.8 days - Average sunshine days in April:
24.4 days - Average sunshine days in May:
24.6 days - Average sunshine days in June:
25.5 days
- Average sunshine days in July:
24.9 days - Average sunshine days in August:
23.1 days - Average sunshine days in September:
24.3 days - Average sunshine days in October:
25.8 days - Average sunshine days in November:
24.4 days - Average sunshine days in December:
22 days
The month with the most sunshine days is October (25.8 days).
The month with the least sunshine days is March (20.8 days).
Average UV index
San Francisco, CA
The months with the highest UV index are April, June, July, August and September (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover
San Francisco, CA
The month with the most cloud cover is March (Cloud cover 36).
The months with the least cloud cover are July and September (Cloud cover 14).
Average visibility
San Francisco, 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 Francisco, California, USA
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