How Many Sunny Days Does San Francisco Get Each Year?

The number of sunny days in San Francisco is a common question for those considering a move to the Bay Area. With its famous fog and microclimates, San Francisco is known for having temperamental weather. If you’re short on time, here’s a quick answer to your question: San Francisco averages around 260 sunny days per year.

In this comprehensive guide, we’ll dive into the details of San Francisco’s sunny day climate. We’ll look at historical weather data to find yearly and monthly sunny day averages. We’ll compare San Francisco to other major U.S. cities and see how it stacks up. And we’ll explore the factors like geography and microclimates that contribute to San Francisco’s unique sunny day patterns.

Sunny Days Per Year in San Francisco

When it comes to the weather in San Francisco, the city is known for its iconic fog and cooler temperatures. However, that doesn’t mean that sunny days are completely absent. Let’s take a closer look at just how many sunny days San Francisco gets each year.

Historical Weather Data

Historical weather data provides valuable insights into the climate patterns of a region. In the case of San Francisco, the city’s weather records go back several decades. By analyzing this data, meteorologists and climate scientists have been able to determine the average number of sunny days in the city.

One authoritative source for weather data is the National Weather Service, which keeps records of daily weather observations from various locations across the United States. Their website,, provides detailed information about the weather patterns in San Francisco.

Yearly Sunny Day Average

On average, San Francisco experiences around 259 sunny days each year. However, it’s important to note that this is an average and not a guarantee. The actual number of sunny days can vary from year to year due to various factors such as weather patterns, marine layer, and foggy conditions.

Despite the reputation for fog, San Francisco still manages to have a significant number of sunny days throughout the year. It’s not uncommon to see locals and visitors alike enjoying the sunshine in popular spots like Golden Gate Park or the waterfront.

Monthly Sunny Day Averages

Breaking down the sunny days by month can provide a clearer picture of when San Francisco tends to have more or fewer sunny days. Here is a rough breakdown of the monthly sunny day averages in San Francisco:

Month Sunny Days
January 11
February 14
March 18
April 20
May 21
June 23
July 25
August 25
September 24
October 22
November 16
December 12

As seen from the monthly breakdown, the number of sunny days generally increases as summer approaches, with July and August having the highest average number of sunny days. However, it’s important to keep in mind that weather patterns can vary, and these averages are just a rough estimate.

So, while San Francisco may not be known for year-round sunshine, it does offer a decent number of sunny days throughout the year for residents and visitors to enjoy.

How San Francisco Compares to Other Cities

When it comes to sunny days, San Francisco is often associated with its famous fog and cooler temperatures. However, the city does have its fair share of sunny days throughout the year. Let’s take a look at how San Francisco compares to other cities in terms of sunny days.

Sunny Days in Los Angeles

Los Angeles, known for its year-round pleasant weather, boasts an impressive number of sunny days. On average, the City of Angels enjoys around 284 sunny days per year. The iconic palm trees and blue skies are a common sight in this sunny Southern California city.

Sunny Days in New York City

New York City, on the other hand, experiences a more variable climate. The Big Apple receives an average of 234 sunny days per year. While it may not have as many sunny days as Los Angeles, New York City still offers plenty of opportunities to soak up the sun in its beautiful parks and rooftop bars.

Sunny Days in Seattle

Seattle, Washington, is often associated with rain and cloudy weather. However, the Emerald City surprises with its number of sunny days. On average, Seattle experiences around 152 sunny days per year. Despite its reputation for rain, there are still many chances to enjoy outdoor activities under the sun in Seattle.

San Francisco vs. Other Cities Summary

Compared to its neighbors, San Francisco falls in the middle when it comes to sunny days. The city experiences around 259 sunny days per year, which is more than Seattle but less than Los Angeles and New York City.

While San Francisco may not have as many sunny days as some other cities, its unique microclimate and stunning landscapes make it a great place to explore regardless of the weather.

For more information on San Francisco’s weather patterns and sunny days, you can visit the Weather Channel or the National Oceanic and Atmospheric Administration.

Why San Francisco Has its Unique Sunny Day Climate

San Francisco is known for its unique climate, characterized by cool summers and mild winters. Despite its reputation for fog and chilly temperatures, the city still experiences a significant number of sunny days each year. Several factors contribute to this distinctive climate.

Coastal Location and Marine Layer

One of the main reasons for San Francisco’s unique sunny day climate is its coastal location. Situated on a peninsula between the Pacific Ocean and the San Francisco Bay, the city is influenced by the cool marine air.

This often results in the formation of a marine layer, a blanket of fog that can cover the city and surrounding areas. However, the marine layer typically burns off by mid-morning, allowing the sun to shine through and provide pleasant weather for the rest of the day.

The marine layer is caused by the temperature difference between the cool ocean water and the warmer land. As the warm air rises over the land, it cools and condenses when it reaches the cooler ocean surface. This condensation forms fog and clouds, which can linger near the coast.

The marine layer is more prevalent during the summer months when the temperature contrast is greater.


San Francisco is also known for its microclimates, which further contribute to its unique sunny day climate. Due to the city’s hilly terrain and varying topography, different neighborhoods can experience different weather conditions at the same time.

Some areas may be shrouded in fog while others enjoy clear skies and sunshine.

The microclimates in San Francisco are a result of the cool ocean air being funneled through gaps in the coastal hills and interacting with the warm air over the land. This creates localized weather patterns that can vary significantly within short distances.

For residents and visitors, this means that while one part of the city may be foggy and cool, another area just a few miles away could be bathed in sunlight.

Rain Shadow Effect

Another factor that contributes to San Francisco’s sunny day climate is the rain shadow effect. The coastal mountains to the east of the city, including the Santa Cruz Mountains, act as a barrier that blocks the incoming moisture-laden winds from the Pacific Ocean.

As a result, the western side of these mountains receives ample rainfall, while the eastern side, where San Francisco is located, experiences much less precipitation.

This rain shadow effect helps to create drier conditions in San Francisco, allowing for more sunny days throughout the year. While the city still receives its fair share of fog and cooler temperatures, the rain shadow effect helps to mitigate the amount of rainfall and contributes to the overall sunnier climate.


To summarize, San Francisco enjoys around 260 sunny days per year on average. This puts the city in the middle of the pack compared to other major U.S. metros. The coastal fog and interesting microclimates contribute to the city’s famously unpredictable weather. Hopefully this guide gave you a comprehensive look at what to expect when it comes to sunny days in San Francisco.

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