Southern California (commonly shortened toSoCal) is ageographic andculturalregion that generally comprises the southern portion of the U.S. state ofCalifornia. Its densely populated coastal region includesGreater Los Angeles (the second-most populousurban agglomeration in theUnited States)^[4][5] andSan Diego County (the second-most populous county in California). The region generally contains ten of California's 58 counties:Los Angeles,San Diego,Orange,Riverside,San Bernardino,Kern,Ventura,Santa Barbara,San Luis Obispo, andImperial counties.

Southern California
Images top to bottom, left to right:Hermosa Beach Pier,Disneyland Resort,Village of La Jolla,Santa Monica Pier,Surfer at Black's Beach,Hollywood Sign,Downtown Los Angeles,San Diego Skyline
Red: The ten counties of Southern California
Country	United States
State	California
Counties	Imperial Kern Los Angeles Orange Riverside San Bernardino San Diego San Luis Obispo Santa Barbara Ventura
Largest city	Los Angeles
Area (10-county)[1]
• Total	56,505 sq mi (146,350 km2)
Population  (2020)[2]
• Total	23,762,904
GDP [3]
• Total	$1.95 trillion (2022)

Although geographically smaller thanNorthern California in land area, Southern California has a higher population, with 23.76 million residents as of the2020 census. The sparsely populateddesert region of California occupies a significant portion (part of which has even beenproposed to be split into a new county due to cultural, economic and geographic differences relative to the rest of the more urban region) of the area: theColorado Desert, along with theColorado River, is located on Southern California's eastern border withArizona, and theMojave Desert shares a border withNevada to the northeast. Southern California's southern border withBaja California is part of theMexico–United States border.

Southern California encompasses eight metropolitan areas (MSAs), three of which together form theGreater Los AngelesCombined Statistical Area (CSA) with over 18 million people, the second-biggest CSA afterthe New York CSA. These three MSAs are theLos Angeles metropolitan area (Los Angeles andOrange counties, with 13.3 million people), theInland Empire (Riverside andSan Bernardino counties, including theCoachella Valley cities, with 4.3 million people), and theOxnard–Thousand Oaks–Ventura metropolitan area (0.8 million people). In addition, Southern California contains theSan Diego metropolitan area with 3.3 million people,Bakersfield metro area with 0.9 million, and theSanta Barbara,San Luis Obispo, andEl Centro (Imperial County) metropolitan areas.

TheSouthern CaliforniaMegaregion (ormegalopolis) is larger still, extending northeast intoLas Vegas,Nevada and south across theMexican border intoTijuana.^[6]

Within Southern California are two major cities,Los Angeles andSan Diego, as well as three of thecountry's largest metropolitan areas.^[7] With a population of approximately 4 million, Los Angeles is the most populous city in California and the second most populous in the United States. South of Los Angeles and with a population of approximately 1.4 million is San Diego, the second most populous city in the state and the eighth most populous in the nation.

The counties ofLos Angeles,San Diego,Orange,Riverside, andSan Bernardino are the five most populous in the state, and are among the top 15 most populous counties in the United States.^[8]

Themotion picture,television andmusic industry are centered in the Los Angeles area in Southern California.Hollywood, a district of Los Angeles, gives its name to the American motion picture industry, which is synonymous with the neighborhood name. Headquartered in Southern California areThe Walt Disney Company (which ownsABC),Sony Pictures,Universal Pictures,MGM,Paramount Pictures, andWarner Bros. Universal, Warner Bros., and Sony also run major record companies.

Southern California is also home to a large surf and skateboard culture. Companies such asVans,Volcom,Quiksilver,No Fear,Stüssy,RVCA, andBody Glove are all headquartered there. SkateboarderTony Hawk; surfersRob Machado,Timmy Curran,Bobby Martinez,Pat O'Connell,Dane Reynolds, andChris Ward live in Southern California. Some of the most famous surf locations are in Southern California as well, includingTrestles,Rincon,The Wedge,Huntington Beach, andMalibu. Some of the world's largestaction sports events, including theX Games,^[9]Boost Mobile Pro,^[10] and theU.S. Open of Surfing, are held in Southern California. The region is also important to the world ofyachting with premier events including the annualTranspacific Yacht Race, orTranspac, from Los Angeles to Hawaii.San Diego Yacht Club hosted the threeAmerica's Cup races from 1988 to 1995. The first modern-eratriathlon was held in San Diego'sMission Bay in 1974. Since then, Southern California, andSan Diego in particular, have become a mecca fortriathlon and multi-sport racing, products, and culture.

Southern California has multiple sports franchises and networks, such asFox Sports Net.

Many of these locals and tourists frequent theSouthern California coast for its beaches. Some of Southern California's most popular beaches areMalibu,Laguna Beach,La Jolla,Manhattan Beach, andHermosa Beach. Southern California is also known for its mountain resort communities, such asBig Bear Lake,Lake Arrowhead, andWrightwood, and their ski resorts, likeBear Mountain,Snow Summit,Snow Valley Mountain Resort, andMountain High. The inland desert city ofPalm Springs is also popular.^[11]

Southern California is generally considered the area of California south of the latitude 35°45'N,^[12] approximately one-third of the state, formed by the northern boundaries ofSan Luis Obispo,Kern, andSan Bernardino counties, which are not exactly a straight line. Another definition for Southern California usesPoint Conception and theTehachapi Mountains as the northern geographical barriers, especially when defining California'sbioregions.^[13][14] In this definition,Owens Valley andDeath Valley are part of the Southern California desert system.^[15] Because of the barrier formed by the Tehachapi andSierra Nevada ranges, cartographerGeorge Wheeler observed in 1876 that Northern California was better connected to Oregon and Nevada than it was to Southern California.^[16]

Following the acquisition of the territory of California by the United States, several pro-slavery politicians attempted to arrange the division of Alta California at 36 degrees, 30 minutes, theline of the Missouri Compromise. Instead, the passing of theCompromise of 1850 enabled California to be admitted to the Union as afree state, preventing the southern half of California from becoming its own separateslave state.

Subsequently, southern Californians dissatisfied with inequitable taxes and land laws attempted several times in the 1850s to achieve a separate statehood or territorial statusseparate from northern California. The only successful proposal, the Pico Act of 1859, was passed by theCalifornia State Legislature and signed by State GovernorJohn B. Weller.^[17] It was approved overwhelmingly by nearly 75 percent of southern California voters to form the proposedTerritory of Colorado. The Pico Act bisected California starting at a latitude of six standard parallels south of theMount Diablo meridian, then ducking southward around part of theCentral Valley before cutting northeast to the California border.^[18] Six standard parallels is 144 miles south ofMount Diablo—which corresponds to the current northern border ofSan Luis Obispo County, at the latitude 35°45'N. The proposal was sent toWashington, D.C., with a strong advocate in SenatorMilton Latham. However, the secession crisis following theelection ofAbraham Lincoln in 1860 and the subsequentAmerican Civil War led to the proposal never coming to a vote.^[19][20]

In 1900, theLos Angeles Times defined Southern California as including "the seven counties of Los Angeles, San Bernardino, Orange, Riverside, San Diego, Ventura, and Santa Barbara." This definition left out San Luis Obispo and Kern counties.^[21]

Southern California was the name of aproposed new state which failed to get on the 2018 California ballot. The ballot measure proposed splitting the existing state into three parts.^[22]

In December 2020, during theCOVID-19 pandemic, the state government led by GovernorGavin Newsom divided the state into five regions for the purpose of issuing stay-at-home orders. The Southern California region consisted of the following counties:Imperial,Inyo,Los Angeles,Mono,Orange,Riverside,San Bernardino,San Diego,San Luis Obispo,Santa Barbara, andVentura. However, Kern County was grouped with other counties of theSan Joaquin Valley, California's central agricultural valley.^[23]

Southern California consists of a heavily developed urban environment, home to some of the largesturban areas in the state, along with theDeserts of California (part of which was evenproposed to become a new county due to cultural, economic and geographic differences relative to the rest of the more urban region)^[35][36][37] that have been left undeveloped. It is the third most populatedmegalopolis in the United States, after theGreat Lakes megalopolis and theNortheast megalopolis. Much of Southern California is famous for its large, spread-out, suburban communities and use of automobiles and highways. The dominant areas are Los Angeles,Orange County,San Diego, andRiverside–San Bernardino, each of which are the centers of their respective metropolitan areas, composed of numerous smaller cities and communities. The urban area is also host to an internationalSan Diego–Tijuana metropolitan region, created by the urban area spilling over intoBaja California.

The main barrier to urbanization along theInterstate 5 corridor isCamp Pendleton. The cities and communities alongInterstate 15 andInterstate 215 are so interrelated thatTemecula andMurrieta have as much connection with theSan Diego metropolitan area as they do with theInland Empire. To the east, theUnited States Census Bureau considers the San Bernardino and Riverside County areas,Riverside-San Bernardino area as a separatemetropolitan area from Los Angeles County. Newly developedexurbs formed in theAntelope Valley, north of Los Angeles, theVictor Valley, and theCoachella Valley with theImperial Valley. Also, population growth was high in theBakersfield-Kern County,Santa Maria, andSan Luis Obispo areas.

Most of Southern California has aMediterranean-like climate, with warm and dry summers, mild and wet winters, where cool weather and freezing temperatures are rare. Southern California contains other types of climates, includingsemi-arid,desert andmountain, with infrequent rain and many sunny days. Summers are hot or warm, and dry, while winters are mild, and rainfall is low to moderate depending on the area. Rain is infrequent, but is often heavy when it does occur, makingflash floods an aspect of living in Southern California. This climatic pattern was alluded to in the hit song "It Never Rains (In Southern California)". While snow is very rare in lower elevations, mountains above 5,000 feet (1,500 m) receive plentiful snowfall in the winter.

Since the first decade of the 21st century,droughts andwildfires have increased in frequency as a result ofclimate change.^[38][39]

Southern California consists of one of the more varied collections of geologic, topographic, and natural ecosystem landscapes in a diversity outnumbering other major regions in the state and country. The region spans from Pacific Oceanislands,shorelines, beaches, andcoastal plains, through theTransverse andPeninsular Ranges with their peaks, and into the large and small interior valleys, to the vastdeserts of California.

Introductory categories include:

• Category: Beaches of Southern California
• Category: Mountain ranges of Southern California
• Category: Rivers of Southern California
• Category: Deserts of California
• Category: Parks in Southern California

Note: Plate boundary faults are indicated with a (#) symbol.

Each year, Southern California has about 10,000 earthquakes. Nearly all of them are too small to be felt. Only several hundred have been greater thanmagnitude (M_w ) 3.0, and only about 15–20 have been greater than M_w  4.0.^[40] California as a whole enacted theAlquist Priolo Special Studies Zone Act in the wake of the1971 San Fernando earthquake. The act prohibits new construction of residential buildings closer than 50 feet (15 m) from a surface rupturing active fault zone. In addition, the act improved safety by requiring new structures (both residential and commercial) to be seismically retrofitted. It also required existing infrastructure to comply.

Since 1972, numerous large magnitude earthquakes have struck Southern California with little widespread damage in part due to act. However, exceptions can be noted for epicenters that lie directly on top of densely populated regions such as the M_w  6.71994 Northridge Earthquake and, to a lesser extent, the smaller M_w  5.52008 Chino Hills earthquake. The Northridge earthquake occurred on a blind-thrust fault directly underneath theSan Fernando Valley, which until the earthquake was previously undiscovered.Seismic retrofitting of existing and new construction is aimed to prevent damage and save lives in the aftermath of a major quake, but it cannot guarantee that buildings will be unscathed if the epicenter is relatively close by.

The1994 Northridge earthquake was particularly destructive, causing a substantial number of deaths, injuries, and structural collapses. The quake caused the most property damage of any earthquake in U.S. history at an estimated $20 billion.^[41]

Many Southern Californiafaults are able to produce a M_w  6.7 earthquake or greater, such as theSan Andreas Fault, which can produce M_w  8.0 or greater. The largest known earthquake in California was the1857 Fort Tejon earthquake that ruptured 200+ miles (320+ kilometers) of the San Andreas Fault fromParkfield toWrightwood. With a recurrence interval of roughly 150 years, this part of the San Andreas fault is well within its window to produce another large earthquake. Along with the southern section of the San Andreas (in thePalm Springs region, which has not ruptured in ~400 years), the entire Southern California portion of the San Andreas Fault is ready to produce a powerful earthquake in the near future.

Notable faults capable of large magnitude events include theSan Jacinto Fault (a splay of the San Andreas that runs directly under the I-10 & I-215 interchange), theNewport–Inglewood-Rose Canyon Fault (located adjacent toSoFi Stadium and responsible forSignal Hill), theElsinore Fault (createdLake Elsinore), theGarlock Fault (which marks boundary between of theSierra Nevada and theMojave Desert), and theHollywood fault (which is within feet ofCapitol Records and is roughly parallel toHollywood Boulevard).

TheUnited States Geological Survey (USGS) has released a California earthquake forecast,^[42] which models earthquake occurrence in California.

This is a partial list of earthquakes in Southern California. For a full list, seeList of earthquakes in California.

Note: Earthquakes with epicenters in the Los Angeles Metro Area are marked with the (#) symbol. Other earthquakes mentioned indicates shaking was felt in the region.

As of the2020 United States census, Southern California has a population of 23,762,904. Despite a reputation for high growth rates, Southern California's population has grown slower than the state average since the 2000s. This is due to California's growth becoming concentrated in the northern part of the state as result of a stronger, tech-oriented economy in theBay Area and an emergingGreater Sacramento region.

Southern California consists of oneCombined Statistical Area, eightMetropolitan Statistical Areas, one internationalmetropolitan area, and multiple metropolitan divisions. The region is home to two extended metropolitan areas that exceed five million in population. These are theGreater Los Angeles Area at 17,786,419, andSan Diego–Tijuana at 5,105,768.^[46][47] Of these metropolitan areas, theLos Angeles-Long Beach-Santa Ana metropolitan area,Riverside-San Bernardino-Ontario metropolitan area, andOxnard-Thousand Oaks-Ventura metropolitan area form Greater Los Angeles;^[48] while theEl Centro metropolitan area andSan Diego-Carlsbad-San Marcos metropolitan area form theSouthern Border Region.^[49][50] North of Greater Los Angeles are theSanta Barbara,San Luis Obispo, andBakersfield metropolitan areas.

Los Angeles (with a population of approximately 3.9 million people) and San Diego (at nearly 1.4 million people) are the two largest cities in all of California, and are among the top eight largest cities in the United States.^[51] In Southern California, there are also 14 cities with more than 200,000 residents and 48 cities over 100,000 residents. Many of Southern California's most developed cities lie along or in close proximity to the coast, with the exception of San Bernardino and Riverside.

• Imperial
• Kern
• Los Angeles
• Orange
• Riverside
• San Bernardino
• San Diego
• San Luis Obispo
• Santa Barbara
• Ventura

Southern California is one of the largest economies in the United States. It is dominated by, and heavily dependent upon, the abundance of petroleum, as opposed to other regions where automobiles are not nearly as dominant, due to the vast majority of transport that runs on this fuel. Southern California is famous for tourism and theentertainment industry. Other industries include software, automotive, aerospace, finance, biomedical, ports and regional logistics. The region was a leader in the housing bubble from 2001 to 2007, and has been heavily impacted by the housing crash.

Since the 1920s, motion pictures, petroleum, and aircraft manufacturing have been major industries. In one of the richest agricultural regions in the U.S., cattle and citrus were major industries until farmlands were turned into suburbs. Although military spending cutbacks have had an impact, aerospace continues to be a major factor.^[52]

Southern California is home to many major business districts. Central business districts (CBD) includeDowntown Los Angeles,Downtown Riverside,Downtown San Bernardino,downtown San Diego, and theSouth Coast Metro. Within the Los Angeles Area are the major business districts ofDowntown Pasadena,Downtown Burbank,Downtown Santa Monica,Downtown Glendale andDowntown Long Beach. Los Angeles proper has many business districts, such asDowntown LA and those liningWilshire Boulevard, includingMid-Wilshire, theMiracle Mile,Downtown Beverly Hills, andWestwood; others includeCentury City andWarner Center in theSan Fernando Valley. The area of Santa Monica and Venice (and perhaps some of Culver City) is informally referred to as "Silicon Beach" because of the concentration of financial and marketing technology-centric firms located in the region.

TheSan Bernardino-Riverside Area maintains the business districts ofDowntown San Bernardino,Hospitality Business/Financial Centre,University District which are in the cities of San Bernardino and Riverside.

In Orange County, has highly developed suburban business centers (also known asedge cities) including theAnaheim–Santa Ana edge city along I-5; and another, theSouth Coast Plaza–John Wayne Airport edge city that stretches from theSouth Coast Metro to theIrvine Business Complex;Newport Center; andIrvine Spectrum.Downtown Santa Ana is an important government, arts and entertainment, and retail district.

Downtown San Diego is the CBD of San Diego, though the city is filled with business districts. These includeCarmel Valley,Del Mar Heights,Mission Valley,Rancho Bernardo,Sorrento Mesa, andUniversity City. Most of these districts are located in Northern San Diego and some withinNorth County regions.

California wine AVA-American Viticultural Areas in southern California:

Southern California is home toLos Angeles International Airport, the second-busiest airport in the United States by passenger volume (seeWorld's busiest airports by passenger traffic) and the third-busiest by international passenger volume (seeBusiest airports in the United States by international passenger traffic);San Diego International Airport, the busiest single-runway airport in the United States;Van Nuys Airport, the world's busiestgeneral aviation airport; major commercial airports atSan Bernardino,Orange County,Bakersfield,Ontario,Burbank, andLong Beach; and numerous smaller commercial and general aviation airports.

Six of the seven lines of thecommuter rail system,Metrolink, run out of downtown Los Angeles, connecting Los Angeles,Ventura, San Bernardino, Riverside, Orange, and San Diego counties with the other line connecting San Bernardino, Riverside, and Orange counties directly.

Southern California is also home to thePort of Los Angeles, the country's busiest commercial port; the adjacentPort of Long Beach, the country's second busiest container port; and thePort of San Diego.

The following table shows all airports listed by the Federal Aviation Association (FAA) as a hub airport:^[53]

Sections of the Southern California freeway system are often referred to by names rather than by the official numbers.

Public institutions in the region include:

University of California (10 campuses total; 5 within the SoCal region)

• Irvine
• Los Angeles
• Riverside
• Santa Barbara
• San Diego

California State University (23 campuses total; 12 within the SoCal region)

Private institutions include:

Numerous parks provide recreation opportunities and open space. Locations include:

Major professional sports teams in Southern California include:

• NFL (American football)Los Angeles Rams,Los Angeles Chargers
• NBA (Basketball)Los Angeles Lakers,Los Angeles Clippers
• MLB (Baseball)Los Angeles Dodgers,Los Angeles Angels,San Diego Padres
• NHL (Ice hockey)Los Angeles Kings,Anaheim Ducks
• MLS (Soccer)LA Galaxy,Los Angeles FC,San Diego FC
• NWSL(Soccer)Angel City FC,San Diego Wave FC
• WNBA(Basketball)Los Angeles Sparks

Southern California also is home to a number of popular NCAA sports programs such as theUCLA Bruins, theUSC Trojans, and theSan Diego State Aztecs. The Bruins and the Trojans both field football teams inNCAA Division I in theBig Ten Conference, and there is a longtimerivalry between the schools.

• Castillo-Munoz, Veronica (2016).The Other California: Land, Identity and Politics on the Mexican Borderlands. University of California Press.
• Deverell, William; Igler, David, eds. (2013).A companion to California history. John Wiley & Sons.
• Fogelson, Robert M. (1967).The Fragmented Metropolis: Los Angeles, 1850–1930., focus on planning, infrastructure, water and business.
• Friedricks, William (1992).Henry E. Huntington and the Creation of Southern California., on Henry Edwards Huntington (1850–1927), railroad executive and collector, who helped build LA and southern California through the Southern Pacific railroad and trolleys.
• Garcia, Matt. (2001).A World of Its Own: Race, Labor and Citrus in the Making of Greater Los Angeles, 1900–1970.
• Garcia, Mario T. (1972). "A Chicano Perspective on San Diego History".Journal of San Diego History.18 (4):14–21.online
• Lotchin, Roger (2002).Fortress California, 1910–1961.excerpt and text search, covers military and industrial roles.
• Mills, James R. (1960).San Diego: Where California Began. San Diego: San Diego Historical Society.{{cite book}}: CS1 maint: publisher location (link)revised edition online
• O'Flaherty, Joseph S. (1972).An End and a Beginning: The South Coast and Los Angeles, 1850–1887.
• O'Flaherty, Joseph S. (1978).Those Powerful Years: The South Coast and Los Angeles, 1887–1917.
• Pryde, Philip R. (2004).San Diego: An Introduction to the Region (4th ed.)., a historical geography
• Shragge, Abraham. (1994). "A new federal city: San Diego during World War II".Pacific Historical Review.63 (3):333–361.doi:10.2307/3640970.JSTOR 3640970.in JSTOR
• Starr, Kevin (1997).The Dream Endures: California Enters the 1940s. pp. 90–114., covers 1880s–1940
• Starr, Kevin (2004).Coast of Dreams: California on the Edge, 1990–2003. pp. 372–381.
• Starr, Kevin (2011).Golden Dreams: California in an Age of Abundance, 1950–1963. pp. 57–87.

• California Historical Society Collection, 1860–1960 –USC Libraries Digital Collections
• Historical Society of Southern California^[usurped]

34°00′N117°00′W / 34.000°N 117.000°W /34.000; -117.000