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San Francisco

Consolidated city-county in California, United States

Top 10 San Francisco related articles

San Francisco
City and County of San Francisco
San Francisco from the Marin Headlands
Nickname(s): 
Motto(s): 
Oro en Paz, Fierro en Guerra (Spanish)
(English: "Gold in Peace, Iron in War")
Anthem: I Left My Heart in San Francisco[2]
San Francisco
Location within the San Francisco Bay Area
San Francisco
Location within California
San Francisco
Location within the contiguous United States
San Francisco
Location within North America
Coordinates: 37°46′39″N 122°24′59″W / 37.77750°N 122.41639°W / 37.77750; -122.41639Coordinates: 37°46′39″N 122°24′59″W / 37.77750°N 122.41639°W / 37.77750; -122.41639
CountryUnited States
StateCalifornia
CountySan Francisco
CSASan Jose–San Francisco–Oakland
MetroSan Francisco–Oakland–Hayward
MissionJune 29, 1776[3]
IncorporatedApril 15, 1850[4]
Founded byJosé Joaquín Moraga
Francisco Palóu
Named forSt. Francis of Assisi
Government
 • TypeMayor–council
 • BodyBoard of Supervisors
 • MayorLondon Breed (D)[5]
 • Supervisors[7]
 • Assembly members[8][9]David Chiu (D)
Phil Ting (D)
 • State senatorScott Wiener (D)[6]
 • United States Representatives[10][11]Nancy Pelosi (D)
Jackie Speier (D)
Area
 • City and county231.91 sq mi (600.65 km2)
 • Land46.91 sq mi (121.51 km2)
 • Water185.00 sq mi (479.15 km2)  80.00%
 • Metro
3,524.4 sq mi (9,128 km2)
Elevation52 ft (16 m)
Highest elevation934 ft (285 m)
Lowest elevation0 ft (0 m)
Population
 • City and county805,235
 • Estimate 
(2019)[16]
881,549
 • Rank4th in California
16th in United States
 • Density18,790.74/sq mi (7,255.12/km2)
 • Metro
4,729,484 (12th)
 • CSA
9,666,055 (5th)
Demonym(s)San Franciscan
San Francisqueño/a
Time zoneUTC−8 (Pacific Time Zone)
 • Summer (DST)UTC−7 (Pacific Daylight Time)
ZIP Codes[17]
List
  • 94102–94105
  • 94107–94112
  • 94114–94134
  • 94137
  • 94139–94147
  • 94151
  • 94158–94161
  • 94163–94164
  • 94172
  • 94177
  • 94188
Area codes415/628[18]
FIPS code06-67000
GNIS feature IDs277593, 2411786
GDP (2019)[19]City—$203.5billion

MSA—$591.9 billion (4th)

CSA—$1.086 trillion (3rd)
Websitesf.gov

San Francisco (/ˌsæn fɹənˈsɪskoʊ/; Spanish for "Saint Francis"), officially the City and County of San Francisco, is a cultural, commercial, and financial center in Northern California. San Francisco is the 16th most populous city in the United States, and the fourth most populous in California, with 881,549 residents as of 2019.[15] It covers an area of about 46.89 square miles (121.4 km2),[20] mostly at the north end of the San Francisco Peninsula in the San Francisco Bay Area, making it the second most densely populated large U.S. city, and the fifth most densely populated U.S. county, behind only four of the five New York City boroughs. San Francisco is part of the 12th-largest metropolitan statistical area in the United States by population, with 4.7 million people, and the fourth-largest by economic output, with GDP of $592 billion in 2019.[21] With San Jose, it forms the fifth most populous combined statistical area in the United States, with 9.67 million residents as of 2019. Colloquial nicknames for San Francisco include SF, San Fran, The City, and Frisco.[22][23]

In 2019, San Francisco was the county with the seventh-highest income in the United States, with a per capita income of $139,405.[24] In the same year, San Francisco proper had a GDP of $203.5 billion, and a GDP per capita of $230,829.[21][25] The CSA San Francisco shares with San Jose and Oakland, with a GDP of $1.09 trillion as of 2019, is the country's third-largest urban economy, following New York City and Los Angeles.[26] Of the 105 primary statistical areas in the U.S. with over 500,000 residents, this CSA had the highest GDP per capita in 2019, at $112,348.[26] San Francisco was ranked 12th in the world and second in the United States on the Global Financial Centres Index as of March 2021, after New York City.[27]

San Francisco was founded on June 29, 1776, when colonists from Spain established the Presidio of San Francisco at the Golden Gate and Mission San Francisco de Asís a few miles away, both named for Francis of Assisi.[3] The California Gold Rush of 1849 brought rapid growth, making it the largest city on the West Coast at the time. San Francisco became a consolidated city-county in 1856.[28] San Francisco's status as the West Coast's largest city peaked between 1870 and 1900, when around 25% of California's population resided in the city proper.[29] After three-quarters of the city was destroyed by the 1906 earthquake and fire,[30] San Francisco was quickly rebuilt, hosting the Panama-Pacific International Exposition nine years later. In World War II, San Francisco was a major port of embarkation for service members shipping out to the Pacific Theater.[31] It then became the birthplace of the United Nations in 1945.[32][33][34] After the war, the confluence of returning servicemen, significant immigration, liberalizing attitudes, along with the rise of the "beatnik" and "hippie" countercultures, the Sexual Revolution, the Peace Movement growing from opposition to United States involvement in the Vietnam War, and other factors led to the Summer of Love and the gay rights movement, cementing San Francisco as a center of liberal activism in the United States. Politically, the city votes strongly along liberal Democratic Party lines.

A popular tourist destination,[35] San Francisco is known for its cool summers, fog, steep rolling hills, eclectic mix of architecture, and landmarks, including the Golden Gate Bridge, cable cars, the former Alcatraz Federal Penitentiary, Fisherman's Wharf, and its Chinatown district. San Francisco is also the headquarters of five major banking institutions and various other companies such as Levi Strauss & Co., Gap Inc., Fitbit, Salesforce.com, Dropbox, Reddit, Square, Inc., Dolby, Airbnb, Pacific Gas and Electric Company, Yelp, Pinterest, Twitter, Uber, Lyft, Mozilla, Wikimedia Foundation, Quizlet, and Craigslist. The city, and the surrounding Bay Area, is a global center of the sciences and arts[36][37] and is home to a number of educational and cultural institutions, such as the University of California, San Francisco (UCSF), the University of San Francisco (USF), San Francisco State University (SFSU), the de Young Museum, the San Francisco Museum of Modern Art, the SFJAZZ Center, and the California Academy of Sciences.

San Francisco Intro articles: 63

History

Yelamu villages in San Francisco
Historical affiliations
Spanish Empire 1776–1821
First Mexican Empire 1821–1823
United Mexican States 1823–1848
 United States 1848–present

The earliest archaeological evidence of human habitation of the territory of the city of San Francisco dates to 3000 BC.[38] The Yelamu group of the Ohlone people resided in a few small villages when an overland Spanish exploration party, led by Don Gaspar de Portolá, arrived on November 2, 1769, the first documented European visit to San Francisco Bay.[39] The first maritime presence occurred on August 5, 1775, when San Carlos—commanded by Juan Manuel de Ayala—became the first ship to anchor in the bay.[40] The following year, on March 28, 1776, the Spanish established the Presidio of San Francisco, followed by a mission, Mission San Francisco de Asís (Mission Dolores), established by the Spanish explorer Juan Bautista de Anza.[3]

Upon independence from Spain in 1821, the area became part of Mexico. Under Mexican rule, the mission system gradually ended, and its lands became privatized. In 1835, William Richardson, a naturalized Mexican citizen of English birth, erected the first independent homestead,[41] near a boat anchorage around what is today Portsmouth Square. Together with Alcalde Francisco de Haro, he laid out a street plan for the expanded settlement, and the town, named Yerba Buena, began to attract American settlers. Commodore John D. Sloat claimed California for the United States on July 7, 1846, during the Mexican–American War, and Captain John B. Montgomery arrived to claim Yerba Buena two days later. Yerba Buena was renamed San Francisco on January 30 of the next year, and Mexico officially ceded the territory to the United States at the end of the war in 1848. Despite its attractive location as a port and naval base, San Francisco was still a small settlement with inhospitable geography.[42]

The California Gold Rush brought a flood of treasure seekers (known as "forty-niners", as in "1849"). With their sourdough bread in tow,[43] prospectors accumulated in San Francisco over rival Benicia,[44] raising the population from 1,000 in 1848 to 25,000 by December 1849.[45] The promise of great wealth was so strong that crews on arriving vessels deserted and rushed off to the gold fields, leaving behind a forest of masts in San Francisco harbor.[46] Some of these approximately 500 abandoned ships were used at times as storeships, saloons, and hotels; many were left to rot and some were sunk to establish title to the underwater lot. By 1851, the harbor was extended out into the bay by wharves while buildings were erected on piles among the ships. By 1870, Yerba Buena Cove had been filled to create new land. Buried ships are occasionally exposed when foundations are dug for new buildings.[47]

California was quickly granted statehood in 1850, and the U.S. military built Fort Point at the Golden Gate and a fort on Alcatraz Island to secure the San Francisco Bay. Silver discoveries, including the Comstock Lode in Nevada in 1859, further drove rapid population growth.[48] With hordes of fortune seekers streaming through the city, lawlessness was common, and the Barbary Coast section of town gained notoriety as a haven for criminals, prostitution, and gambling.[49]

Entrepreneurs sought to capitalize on the wealth generated by the Gold Rush. Early winners were the banking industry, with the founding of Wells Fargo in 1852 and the Bank of California in 1864. Development of the Port of San Francisco and the establishment in 1869 of overland access to the eastern U.S. rail system via the newly completed Pacific Railroad (the construction of which the city only reluctantly helped support[50]) helped make the Bay Area a center for trade. Catering to the needs and tastes of the growing population, Levi Strauss opened a dry goods business and Domingo Ghirardelli began manufacturing chocolate. Chinese immigrants made the city a polyglot culture, drawn to "Old Gold Mountain", creating the city's Chinatown quarter. In 1870, Asians made up 8% of the population.[51] The first cable cars carried San Franciscans up Clay Street in 1873. The city's sea of Victorian houses began to take shape, and civic leaders campaigned for a spacious public park, resulting in plans for Golden Gate Park. San Franciscans built schools, churches, theaters, and all the hallmarks of civic life. The Presidio developed into the most important American military installation on the Pacific coast.[52] By 1890, San Francisco's population approached 300,000, making it the eighth-largest city in the United States at the time. Around 1901, San Francisco was a major city known for its flamboyant style, stately hotels, ostentatious mansions on Nob Hill, and a thriving arts scene.[53] The first North American plague epidemic was the San Francisco plague of 1900–1904.[54]

At 5:12 am on April 18, 1906, a major earthquake struck San Francisco and northern California. As buildings collapsed from the shaking, ruptured gas lines ignited fires that spread across the city and burned out of control for several days. With water mains out of service, the Presidio Artillery Corps attempted to contain the inferno by dynamiting blocks of buildings to create firebreaks.[55] More than three-quarters of the city lay in ruins, including almost all of the downtown core.[30] Contemporary accounts reported that 498 people lost their lives, though modern estimates put the number in the several thousands.[56] More than half of the city's population of 400,000 was left homeless.[57] Refugees settled temporarily in makeshift tent villages in Golden Gate Park, the Presidio, on the beaches, and elsewhere. Many fled permanently to the East Bay.

"Not in history has a modern imperial city been so completely destroyed. San Francisco is gone." –Jack London after the 1906 earthquake and fire[58]

Rebuilding was rapid and performed on a grand scale. Rejecting calls to completely remake the street grid, San Franciscans opted for speed.[59] Amadeo Giannini's Bank of Italy, later to become Bank of America, provided loans for many of those whose livelihoods had been devastated. The influential San Francisco Planning and Urban Research Association or SPUR was founded in 1910 to address the quality of housing after the earthquake.[60] The earthquake hastened development of western neighborhoods that survived the fire, including Pacific Heights, where many of the city's wealthy rebuilt their homes.[61] In turn, the destroyed mansions of Nob Hill became grand hotels. City Hall rose again in splendid Beaux Arts style, and the city celebrated its rebirth at the Panama–Pacific International Exposition in 1915.[62]

It was during this period San Francisco built some of its most important infrastructure. Civil Engineer Michael O'Shaughnessy was hired by San Francisco Mayor James Rolph as chief engineer for the city in September 1912 to supervise the construction of the Twin Peaks Reservoir, the Stockton Street Tunnel, the Twin Peaks Tunnel, the San Francisco Municipal Railway, the Auxiliary Water Supply System, and new sewers. San Francisco's streetcar system, of which the J, K, L, M, and N lines survive today, was pushed to completion by O'Shaughnessy between 1915 and 1927. It was the O'Shaughnessy Dam, Hetch Hetchy Reservoir, and Hetch Hetchy Aqueduct that would have the largest effect on San Francisco.[63] An abundant water supply enabled San Francisco to develop into the city it has become today.

The Bay Bridge, under construction in 1935, took forty months to complete.

In ensuing years, the city solidified its standing as a financial capital; in the wake of the 1929 stock market crash, not a single San Francisco-based bank failed.[64] Indeed, it was at the height of the Great Depression that San Francisco undertook two great civil engineering projects, simultaneously constructing the San Francisco–Oakland Bay Bridge and the Golden Gate Bridge, completing them in 1936 and 1937, respectively. It was in this period that the island of Alcatraz, a former military stockade, began its service as a federal maximum security prison, housing notorious inmates such as Al Capone, and Robert Franklin Stroud, the Birdman of Alcatraz. San Francisco later celebrated its regained grandeur with a World's fair, the Golden Gate International Exposition in 1939–40, creating Treasure Island in the middle of the bay to house it.

During World War II, the Hunters Point Naval Shipyard became a hub of activity, and Fort Mason became the primary port of embarkation for service members shipping out to the Pacific Theater of Operations.[31] The explosion of jobs drew many people, especially African Americans from the South, to the area. After the end of the war, many military personnel returning from service abroad and civilians who had originally come to work decided to stay. The United Nations Charter creating the United Nations was drafted and signed in San Francisco in 1945 and, in 1951, the Treaty of San Francisco re-established peaceful relations between Japan and the Allied Powers.[65]

Urban planning projects in the 1950s and 1960s involved widespread destruction and redevelopment of west-side neighborhoods and the construction of new freeways, of which only a series of short segments were built before being halted by citizen-led opposition.[66] The onset of containerization made San Francisco's small piers obsolete, and cargo activity moved to the larger Port of Oakland.[67] The city began to lose industrial jobs and turned to tourism as the most important segment of its economy.[68] The suburbs experienced rapid growth, and San Francisco underwent significant demographic change, as large segments of the white population left the city, supplanted by an increasing wave of immigration from Asia and Latin America.[69][70] From 1950 to 1980, the city lost over 10 percent of its population.

The Transamerica Pyramid was the tallest building in San Francisco until 2016, when Salesforce Tower surpassed it.

Over this period, San Francisco became a magnet for America's counterculture. Beat Generation writers fueled the San Francisco Renaissance and centered on the North Beach neighborhood in the 1950s.[71] Hippies flocked to Haight-Ashbury in the 1960s, reaching a peak with the 1967 Summer of Love.[72] In 1974, the Zebra murders left at least 16 people dead.[73] In the 1970s, the city became a center of the gay rights movement, with the emergence of The Castro as an urban gay village, the election of Harvey Milk to the Board of Supervisors, and his assassination, along with that of Mayor George Moscone, in 1978.[74]

Bank of America completed 555 California Street in 1969 and the Transamerica Pyramid was completed in 1972,[75] igniting a wave of "Manhattanization" that lasted until the late 1980s, a period of extensive high-rise development downtown.[76] The 1980s also saw a dramatic increase in the number of homeless people in the city, an issue that remains today, despite many attempts to address it.[77] The 1989 Loma Prieta earthquake caused destruction and loss of life throughout the Bay Area. In San Francisco, the quake severely damaged structures in the Marina and South of Market districts and precipitated the demolition of the damaged Embarcadero Freeway and much of the damaged Central Freeway, allowing the city to reclaim The Embarcadero as its historic downtown waterfront and revitalizing the Hayes Valley neighborhood.

Two recent decades have seen two booms driven by the internet industry. First was the dot-com boom of the late 1990s, startup companies invigorated the San Francisco economy. Large numbers of entrepreneurs and computer application developers moved into the city, followed by marketing, design, and sales professionals, changing the social landscape as once-poorer neighborhoods became increasingly gentrified.[78] Demand for new housing and office space ignited a second wave of high-rise development, this time in the South of Market district.[79] By 2000, the city's population reached new highs, surpassing the previous record set in 1950. When the bubble burst in 2001, many of these companies folded and their employees were laid off. Yet high technology and entrepreneurship remain mainstays of the San Francisco economy. By the mid-2000s (decade), the social media boom had begun, with San Francisco becoming a popular location for tech offices and a common place to live for people employed in Silicon Valley companies such as Apple and Google.[80]

The Ferry Station Post Office Building, Armour & Co. Building, Atherton House, and YMCA Hotel are historic buildings among dozens of historical landmarks in the city according to the National Register of Historic Places listings in San Francisco.

San Francisco History articles: 124

Geography

The San Francisco Peninsula

San Francisco is located on the West Coast of the United States at the north end of the San Francisco Peninsula and includes significant stretches of the Pacific Ocean and San Francisco Bay within its boundaries. Several picturesque islandsAlcatraz, Treasure Island and the adjacent Yerba Buena Island, and small portions of Alameda Island, Red Rock Island, and Angel Island—are part of the city. Also included are the uninhabited Farallon Islands, 27 miles (43 km) offshore in the Pacific Ocean. The mainland within the city limits roughly forms a "seven-by-seven-mile square", a common local colloquialism referring to the city's shape, though its total area, including water, is nearly 232 square miles (600 km2).

There are more than 50 hills within the city limits.[81] Some neighborhoods are named after the hill on which they are situated, including Nob Hill, Potrero Hill, and Russian Hill. Near the geographic center of the city, southwest of the downtown area, are a series of less densely populated hills. Twin Peaks, a pair of hills forming one of the city's highest points, forms an overlook spot. San Francisco's tallest hill, Mount Davidson, is 928 feet (283 m) high and is capped with a 103-foot (31 m) tall cross built in 1934.[82] Dominating this area is Sutro Tower, a large red and white radio and television transmission tower.

The nearby San Andreas and Hayward Faults are responsible for much earthquake activity, although neither physically passes through the city itself. The San Andreas Fault caused the earthquakes in 1906 and 1989. Minor earthquakes occur on a regular basis. The threat of major earthquakes plays a large role in the city's infrastructure development. The city constructed an auxiliary water supply system and has repeatedly upgraded its building codes, requiring retrofits for older buildings and higher engineering standards for new construction.[83] However, there are still thousands of smaller buildings that remain vulnerable to quake damage.[84] USGS has released the California earthquake forecast which models earthquake occurrence in California.[85]

San Francisco's shoreline has grown beyond its natural limits. Entire neighborhoods such as the Marina, Mission Bay, and Hunters Point, as well as large sections of the Embarcadero, sit on areas of landfill. Treasure Island was constructed from material dredged from the bay as well as material resulting from the excavation of the Yerba Buena Tunnel through Yerba Buena Island during the construction of the Bay Bridge. Such land tends to be unstable during earthquakes. The resulting soil liquefaction causes extensive damage to property built upon it, as was evidenced in the Marina district during the 1989 Loma Prieta earthquake.[86] Most of the city's natural watercourses, such as Islais Creek and Mission Creek, have been culverted and built over, although the Public Utilities Commission is studying proposals to daylight or restore some creeks.[87]

Cityscape

Aerial view from the west in April 2018. San Francisco is seen in the foreground, with Oakland in the background.

Neighborhoods

San Francisco's Chinatown is the oldest (and one of the largest) in North America.

The historic center of San Francisco is the northeast quadrant of the city anchored by Market Street and the waterfront. It is here that the Financial District is centered, with Union Square, the principal shopping and hotel district, and the Tenderloin nearby. Cable cars carry riders up steep inclines to the summit of Nob Hill, once the home of the city's business tycoons, and down to the waterfront tourist attractions of Fisherman's Wharf, and Pier 39, where many restaurants feature Dungeness crab from a still-active fishing industry. Also in this quadrant are Russian Hill, a residential neighborhood with the famously crooked Lombard Street; North Beach, the city's Little Italy and the former center of the Beat Generation; and Telegraph Hill, which features Coit Tower. Abutting Russian Hill and North Beach is San Francisco's Chinatown, the oldest Chinatown in North America.[88][89][90][91] The South of Market, which was once San Francisco's industrial core, has seen significant redevelopment following the construction of Oracle Park and an infusion of startup companies. New skyscrapers, live-work lofts, and condominiums dot the area. Further development is taking place just to the south in Mission Bay area, a former railroad yard, which now has a second campus of the University of California, San Francisco and Chase Center, which opened in 2019 as the new home of the Golden State Warriors.[92]

West of downtown, across Van Ness Avenue, lies the large Western Addition neighborhood, which became established with a large African American population after World War II. The Western Addition is usually divided into smaller neighborhoods including Hayes Valley, the Fillmore, and Japantown, which was once the largest Japantown in North America but suffered when its Japanese American residents were forcibly removed and interned during World War II. The Western Addition survived the 1906 earthquake with its Victorians largely intact, including the famous "Painted Ladies", standing alongside Alamo Square. To the south, near the geographic center of the city is Haight-Ashbury, famously associated with 1960s hippie culture. The Haight is now home to some expensive boutiques[93] and a few controversial chain stores,[94] although it still retains some bohemian character.

North of the Western Addition is Pacific Heights, an affluent neighborhood that features the homes built by wealthy San Franciscans in the wake of the 1906 earthquake. Directly north of Pacific Heights facing the waterfront is the Marina, a neighborhood popular with young professionals that was largely built on reclaimed land from the Bay.[95]

In the south-east quadrant of the city is the Mission District—populated in the 19th century by Californios and working-class immigrants from Germany, Ireland, Italy, and Scandinavia. In the 1910s, a wave of Central American immigrants settled in the Mission and, in the 1950s, immigrants from Mexico began to predominate.[96] In recent years, gentrification has changed the demographics of parts of the Mission from Latino, to twenty-something professionals. Noe Valley to the southwest and Bernal Heights to the south are both increasingly popular among young families with children. East of the Mission is the Potrero Hill neighborhood, a mostly residential neighborhood that features sweeping views of downtown San Francisco. West of the Mission, the area historically known as Eureka Valley, now popularly called the Castro, was once a working-class Scandinavian and Irish area. It has become North America's first gay village, and is now the center of gay life in the city.[97] Located near the city's southern border, the Excelsior District is one of the most ethnically diverse neighborhoods in San Francisco. The predominantly African American Bayview-Hunters Point in the far southeast corner of the city is one of the poorest neighborhoods and suffers from a high rate of crime, though the area has been the focus of several revitalizing and controversial urban renewal projects.

The construction of the Twin Peaks Tunnel in 1918 connected southwest neighborhoods to downtown via streetcar, hastening the development of West Portal, and nearby affluent Forest Hill and St. Francis Wood. Further west, stretching all the way to the Pacific Ocean and north to Golden Gate Park lies the vast Sunset District, a large middle-class area with a predominantly Asian population.[98]

The northwestern quadrant of the city contains the Richmond, also a mostly middle-class neighborhood north of Golden Gate Park, home to immigrants from other parts of Asia as well as many Russian and Ukrainian immigrants. Together, these areas are known as The Avenues. These two districts are each sometimes further divided into two regions: the Outer Richmond and Outer Sunset can refer to the more western portions of their respective district and the Inner Richmond and Inner Sunset can refer to the more eastern portions.

Many piers remained derelict for years until the demolition of the Embarcadero Freeway reopened the downtown waterfront, allowing for redevelopment. The centerpiece of the port, the Ferry Building, while still receiving commuter ferry traffic, has been restored and redeveloped as a gourmet marketplace.

Climate

San Francisco has a warm-summer Mediterranean climate (Köppen Csb) characteristic of California's coast, with moist mild winters and dry summers.[99] San Francisco's weather is strongly influenced by the cool currents of the Pacific Ocean on the west side of the city, and the water of San Francisco Bay to the north and east. This moderates temperature swings and produces a remarkably mild year-round climate with little seasonal temperature variation.

Fog is a regular feature of San Francisco summers.

Among major U.S. cities, San Francisco has the coolest daily mean, maximum, and minimum temperatures for June, July, and August.[100] During the summer, rising hot air in California's interior valleys creates a low pressure area that draws winds from the North Pacific High through the Golden Gate, which creates the city's characteristic cool winds and fog.[101] The fog is less pronounced in eastern neighborhoods and during the late summer and early fall. As a result, the year's warmest month, on average, is September, and on average, October is warmer than July, especially in daytime.

Because of its sharp topography and maritime influences, San Francisco exhibits a multitude of distinct microclimates. The high hills in the geographic center of the city are responsible for a 20% variance in annual rainfall between different parts of the city. They also protect neighborhoods directly to their east from the foggy and sometimes very cold and windy conditions experienced in the Sunset District; for those who live on the eastern side of the city, San Francisco is sunnier, with an average of 260 clear days, and only 105 cloudy days per year.

Temperatures reach or exceed 80 °F (27 °C) on an average of only 21 and 23 days a year at downtown and San Francisco International Airport (SFO), respectively.[102] The dry period of May to October is mild to warm, with the normal monthly mean temperature peaking in September at 62.7 °F (17.1 °C).[102] The rainy period of November to April is slightly cooler, with the normal monthly mean temperature reaching its lowest in January at 51.3 °F (10.7 °C).[102] On average, there are 73 rainy days a year, and annual precipitation averages 23.65 inches (601 mm).[102] Variation in precipitation from year to year is high. Above average rain years are often associated with warm El Niño conditions in the Pacific while dry years often occur in cold water La Niña periods. In 2013 (a "La Niña" year), a record low 5.59 in (142 mm) of rainfall was recorded at downtown San Francisco, where records have been kept since 1849.[102] Snowfall in the city is very rare, with only 10 measurable accumulations recorded since 1852, most recently in 1976 when up to 5 inches (13 cm) fell on Twin Peaks.[103][104]

The highest recorded temperature at the official National Weather Service downtown observation station[a] was 106 °F (41 °C) on September 1, 2017.[106] The lowest recorded temperature was 27 °F (−3 °C) on December 11, 1932.[107] The National Weather Service provides a helpful visual aid[108] graphing the information in the table below to display visually by month the annual typical temperatures, the past year's temperatures, and record temperatures.

San Francisco falls under the USDA 10b Plant hardiness zone.[109][110]

Climate data for San Francisco (downtown),[b] 1981–2010 normals,[c] extremes 1849–present
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °F (°C) 79
(26)
81
(27)
87
(31)
94
(34)
97
(36)
103
(39)
98
(37)
98
(37)
106
(41)
102
(39)
86
(30)
76
(24)
106
(41)
Mean maximum °F (°C) 67.3
(19.6)
72.5
(22.5)
75.7
(24.3)
82.3
(27.9)
82.7
(28.2)
86.0
(30.0)
83.1
(28.4)
85.5
(29.7)
89.6
(32.0)
88.1
(31.2)
76.1
(24.5)
66.4
(19.1)
94.3
(34.6)
Average high °F (°C) 56.9
(13.8)
60.2
(15.7)
61.8
(16.6)
63.1
(17.3)
64.3
(17.9)
66.4
(19.1)
66.5
(19.2)
68.1
(20.1)
70.2
(21.2)
69.2
(20.7)
63.1
(17.3)
57.1
(13.9)
63.9
(17.7)
Daily mean °F (°C) 51.3
(10.7)
53.9
(12.2)
55.1
(12.8)
56.2
(13.4)
57.6
(14.2)
59.6
(15.3)
60.3
(15.7)
61.6
(16.4)
62.7
(17.1)
61.5
(16.4)
56.6
(13.7)
51.6
(10.9)
57.3
(14.1)
Average low °F (°C) 45.7
(7.6)
47.5
(8.6)
48.5
(9.2)
49.2
(9.6)
51.0
(10.6)
52.8
(11.6)
54.1
(12.3)
55.1
(12.8)
55.1
(12.8)
53.7
(12.1)
50.1
(10.1)
46.1
(7.8)
50.7
(10.4)
Mean minimum °F (°C) 40.3
(4.6)
41.8
(5.4)
43.6
(6.4)
45.1
(7.3)
47.7
(8.7)
50.2
(10.1)
51.5
(10.8)
52.6
(11.4)
52.0
(11.1)
49.6
(9.8)
44.2
(6.8)
40.1
(4.5)
38.2
(3.4)
Record low °F (°C) 29
(−2)
31
(−1)
33
(1)
40
(4)
42
(6)
46
(8)
47
(8)
46
(8)
47
(8)
43
(6)
38
(3)
27
(−3)
27
(−3)
Average rainfall inches (mm) 4.50
(114)
4.46
(113)
3.26
(83)
1.46
(37)
0.70
(18)
0.16
(4.1)
0.00
(0.00)
0.06
(1.5)
0.21
(5.3)
1.12
(28)
3.16
(80)
4.56
(116)
23.65
(601)
Average rainy days (≥ 0.01 in) 11.7 11.1 11.0 6.5 3.8 1.5 0.3 1.0 1.7 3.9 8.9 11.6 73.0
Average relative humidity (%) 80 77 75 72 72 71 75 75 73 71 75 78 75
Mean monthly sunshine hours 185.9 207.7 269.1 309.3 325.1 311.4 313.3 287.4 271.4 247.1 173.4 160.6 3,061.7
Percent possible sunshine 61 69 73 78 74 70 70 68 73 71 57 54 69
Source 1: NOAA (sun 1961–1974)[102][111][112]
Source 2: Met Office for humidity[113]

Flora and fauna

Historically, tule elk were present in San Francisco County, based on archeological evidence of elk remains in at least five different Native American shellmounds: at Hunter's Point, Fort Mason, Stevenson Street, Market Street, and Yerba Buena.[114][115] Perhaps the first historical observer record was from the De Anza Expedition on March 23, 1776. Herbert Eugene Bolton wrote about the expedition camp at Mountain Lake, near the southern end of today's Presidio: "Round about were grazing deer, and scattered here and there were the antlers of large elk."[116] Also, when Richard Henry Dana Jr. visited San Francisco Bay in 1835, he wrote about vast elk herds near the Golden Gate: on December 27 "...we came to anchor near the mouth of the bay, under a high and beautifully sloping hill, upon which herds of hundreds and hundreds of red deer [note: "red deer" is the European term for "elk"], and the stag, with his high branching antlers, were bounding about...", although it is not clear whether this was the Marin side or the San Francisco side.[117]

San Francisco Geography articles: 91