The statistics for Ventura, Los Angeles, Orange, Riverside and San Bernardino counties.
| Year | Los Angeles | orange | San Bernardino | Riverside | Ventura | total | grow |
| 1900 | 170,000 | 20,000 | 28,000 | 18,000 | 14,000 | 250,000 | |
| 1910 | 504,000 | 34,000 | 57,000 | 35,000 | 18,000 | 648,000 | +398,000 |
| 1920 | 936,000 | 61,000 | 73,000 | 50,000 | 29,000 | 1,149,000 | +501,000 |
| 1930 | 2,208,000 | 119,000 | 134,000 | 81,000 | 55,000 | 2,597,000 | +1,448,000 |
| 1940 | 2,786,000 | 131,000 | 161,000 | 106,000 | 70,000 | 3,254,000 | +657,000 |
| 1950 | 4,152,000 | 216,000 | 282,000 | 170,000 | 115,000 | 4,935,000 | +1,681,000 |
| 1960 | 6,039,000 | 704,000 | 504,000 | 306,000 | 199,000 | 7,752,000 | +2,817,000 |
| 1970 | 7,042,000 | 1,420,000 | 684,000 | 459,000 | 376,000 | 9,981,000 | +2,229,000 |
| 1980 | 7,477,000 | 1,933,000 | 895,000 | 663,000 | 529.000 | 11,497,000 | +1,516,000 |
| 1990 | 8,863,000 | 2,411,000 | 1,418,000 | 1,170,000 | 669.000 | 14,531,000 | +3,034,000 |
| 2000 | 9,519,000 | 2,846,000 | 1,709,000 | 1,545,000 | 753,000 | 16,372,000 | +1,841,000 |
| 2010 | 9,819,000 | 3,010,000 | 2,035,000 | 2,190,000 | 823,000 | 17,877,000 | +1,505,000 |
| 2020 | 9,989,000 | 3,184,000 | 2,183,000 | 2,423,000 | 843,000 | 18,622,000 | +745,000 |
| 2021 | 9,830,000 | 3,168,000 | 2,195,000 | 2,458,000 | 840,000 | 18,491,000 | -131,000 |
Los Angeles County
According to collegesanduniversitiesinusa, Los Angeles County, with a population of 9.8 million, has more inhabitants than all states west of the Mississippi River except Texas and California themselves. In addition to the city of Los Angeles, there are also numerous older suburbs south, east and north of Los Angeles. The region is densely populated and industrial in character. The ports of Long Beach are particularly important, as are the industrial valleys east of Los Angeles. The northern San Fernando Valley is somewhat isolated from the rest of the urban area because of the Santa Monica Mountains to the south. In the north of Los Angeles County are eccentrically located suburbs such as Palmdale and Lancaster, in 2010 this exurban area had 350,000 inhabitants.
Ventura County
Located west of Los Angeles County, Ventura County is relatively urbanized to the south, but still has many undeveloped agricultural areas. In addition, the interior of Ventura County is sparsely populated and mountainous. The eastern part of Ventura County has suburbs like Simi Valley and Thousand Oaks that are more or less an extension of the city of Los Angeles, the western cities like Oxnard and Ventura are cities in their own right. Despite its proximity to Los Angeles, Ventura County has not been urbanized at a rapid rate, and despite the presence of large areas of flat land that could be developed, Ventura County did not grow faster than the US average between 2000 and 2010.
Orange County
Orange County is almost entirely suburban in character and has little industry. Despite this, there is a lot of employment, especially around the edge city of Irvine, but also in Anaheim and Santa Ana. The suburbs here have developed from north to south and most of Orange County is now built up. Popular are the long sandy beaches such as Huntington Beach, Newport Beach and Laguna Beach. Northern Orange County has a lot of activity in the logistics sector. Orange County’s growth has slowed to well below the US average since the 1990s because of limited space for new residential development.
San Bernardino County
San Bernardino County includes the northern part of the so-called Inland Empire. Most of San Bernardino County is uninhabited desert. The southwestern part is urbanized with quite a lot of industry, especially around the city of Ontario. The suburbs of Los Angeles County merge seamlessly into the suburbs of San Bernardino County. The part of San Bernardino County that borders the Los Angeles region is almost completely built up. The growth has spread over the Cajon Pass to the Victor Valley, an exurba- tional area that in 2010 had more than 300,000 inhabitants. San Bernardino County borders both Arizona and Nevada. The very sparsely populated northeast of San Bernardino County is a short distance from Las Vegas.
Riverside County
Riverside County is located south of San Bernardino County, the western portion of which is urbanized. Like San Bernardino County, Riverside County also has vast desert areas. Urbanization in Riverside County has grown less strongly than suburbs to the west. Riverside County is less industrial in character than San Bernardino County. Riverside County’s southern suburbs are closer to San Diego than to Los Angeles.
To the east of the suburbs is the Coachella Valley, a still isolated suburban area with approximately 350,000 inhabitants in 2010, which is usually not considered part of the urban area of the Los Angeles region, but also has no clear center. The city of Indio is the largest. In the Coachella Valley, many suburbs have been built around golf courses. A small part of the population drives the enormous distance to Los Angeles every day for work, a journey of more than 3 hours one way during rush hour. The eastern half of Riverside County is mostly desert and mountains. Riverside County extends to the Arizona border, the eastern portion being closer to Phoenix than to Los Angeles.
