Monthly weather forecast and climate
San Francisco, CA

A beautiful dusk view of the Golden Gate Bridge in San Francisco, California, with clear calm waters below, and a foggy formation beyond
A beautiful dusk view of the Golden Gate Bridge in San Francisco, California, with clear calm waters below, and a foggy formation beyond
San Francisco has a Mediterranean type of climate (Köppen climate classification Csb) with warm and dry summers and wet and mild winters. The technology hub of the United States lies on its West Coast on the San Francisco Peninsula and stretches up to the San Francisco Bay and the Pacific Ocean. The Pacific Ocean, the California Cold Current, and the surrounding hills have a significant influence on the climate.

San Francisco exhibits different microclimates due to its varied geography and maritime effects. Temperature variations are remarkably low throughout the year, but they often vary across the city's various microclimates. Summers are warm with characteristic foggy conditions due to the cold currents that flow along the coast. Average high temperatures are at a warm 70°F (21.1°C) during the summer, while average low temperatures drop to 45°F (7.2°C) in peak winter. Winters are mild and wet, with most of the rainfall of 19" (482.6mm) occurring during the winter months. Snow is rare, but some areas of San Francisco are subject to frosty conditions.
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San Francisco is a popular global tourist destination due to its mild weather, technology landscape, and numerous attractions.
Summer from June to September is the best time for a visit when the average temperatures are in the low fifties to the low seventies. San Francisco has the mildest average summer temperatures compared to most of the cities in the United States. Winter months are mild, but they are wet with the occurrence of most of the annual rainfall.
Spring and autumn have fine weather, but also tend to be damp compared to the magnificent summer.

Winter is mild and wet and subject to a majority of the annual precipitation. The worst season to visit San Francisco is during winter, as the average low temperatures drop to the mid 40°F (4.4°C).
Rainfall tends to be heavy and persistent as intermittent winter storms bring substantial rain. Winter has short days, and the daily sunshine lasts for only 5 hours. Nights are sometimes chilly, but the temperatures rarely drop to freezing.

San Francisco is vulnerable to earthquakes as it lies in the vicinity of the San Andreas Fault and the Hayward Fault. Minor earthquakes occur regularly, but they do not pose significant threats due to upgraded building codes. San Francisco's infrastructure development faces a threat from major earthquakes similar to other cities that lie in the Pacific Ring of Fire in California.

January is the wettest month with 4.9" (124.5mm) of rainfall and the coldest with an average low temperature of 45°F (7.2°C). Weather in January »

February is the last month of winter in San Francisco with average lows and highs in a cold range of 48°F (8.9°C) to 60°F (15.6°C) and frosty nights. Weather in February »

Spring starts in March and brings warm weather, with the humidity reducing to 72%. Average temperatures gradually rise to an agreeable 49°F (9.4°C) to 61°F (16.1°C). Weather in March »

San Francisco is mostly sunny, with the warm average daily temperatures of 63°F (17.2°C). Ample daily sunshine of 10 hours is an excellent time to explore the city. Weather in April »

The cold disappears by May with the average lows at 51°F (10.6°C) and the average highs of 64°F (17.8°C). May is sunny with the highest number of daily sunshine hours at 11. Weather in May »

June is a popular summer month in San Francisco and sees an influx of tourists as the average temperatures are in a pleasant range of 53°F (11.7°C) to 66°F (18.9°C). Weather in June »

Average day temperatures at 67°F (19.4°C) and daily sunshine of 11 hours make a beautiful time to explore the trails amongst the redwood trees in the Muir Woods National Monument on Mount Tamalpais. Weather in July »

August is a warm month during the summer season with the highest average low temperature of the year at 55°F (12.8°C), and experiences average high temperatures up to 68°F (20°C). Weather in August »

September starts the autumn season and is the hottest month of the year, with average daily highs at 70°F (21.1°C). Weather in September »

October is mild, with the average lows dropping to 53°F (11.7°C) and the first presence of rain. San Francisco has remarkable weather with a small temperature difference in the lows and highs. Weather in October »

November brings wetness with the rainfall at 3" (76.2mm) and a few rainy days. The temperatures gradually cool down with average nightly lows in the 50°F (10°C). Weather in November »

December is the start of winter with cold and wet weather conditions. Average highs are mild 57°F (13.9°C), while average lows are cold 46°F (7.8°C). Weather in December »

What is the coldest month in San Francisco?

January is the coldest month in San Francisco, California, with an average high-temperature of 56.8°F (13.8°C) and an average low-temperature of 45.7°F (7.6°C).

How much does it rain in San Francisco?

In San Francisco, California, during the entire year, the rain falls for 73 days, and collects up to 23.1" (588mm) of precipitation.

What is the wettest month in San Francisco?

January is the month with the most rainfall in San Francisco. Rain falls for 11.7 days and accumulates 4.9" (125mm) of precipitation.

What is the driest month in San Francisco?

The month with the least rainfall is July when the rain falls for 0.3 days and typically collects 0" (1mm) of precipitation.

What is the warmest month in San Francisco?

With an average high-temperature of 70.2°F (21.2°C) and an average low-temperature of 55°F (12.8°C), September is the warmest month in San Francisco, California.
Average temperature - San Francisco, CA
Average rainfall - San Francisco, CA
Average rainfall days - San Francisco, CA

The month with the highest number of rainy days is January (11.7 days).
The month with the lowest number of rainy days is July (0.3 days).

Average sea temperature - San Francisco, CA

The best month for swimming (with the highest average sea temperature) is September (14.1°C).
Coldest months (with the lowest average sea temperature) are April, May and June (11.7°C).

Average daylight / Average sunshine - San Francisco, CA