The Southern California Megaregion (or megalopolis) is larger still, extending northeast into Las Vegas, Nevada and south across the Mexican border into Tijuana.

[6] Within Southern California are two major cities, Los Angeles and San Diego, as well as three of the country's largest metropolitan areas.

[8] The motion picture, television and music industry are centered in the Los Angeles area in Southern California.

Skateboarder Tony Hawk; surfers Rob Machado, Timmy Curran, Bobby Martinez, Pat O'Connell, Dane Reynolds, and Chris Ward live in Southern California.

Some of the most famous surf locations are in Southern California as well, including Trestles, Rincon, The Wedge, Huntington Beach, and Malibu.

Some of the world's largest action sports events, including the X Games,[9] Boost Mobile Pro,[10] and the U.S. Open of Surfing, are held in Southern California.

[18] Six standard parallels is 144 miles south of Mount Diablo—which corresponds to the current northern border of San Luis Obispo County, at the latitude 35°45'N.

However, the secession crisis following the election of Abraham Lincoln in 1860 and the subsequent American Civil War led to the proposal never coming to a vote.

Also, population growth was high in the Bakersfield-Kern County, Santa Maria, and San Luis Obispo areas.

Most of Southern California has a Mediterranean-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, including semi-arid, desert and mountain, 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, making flash floods an aspect of living in Southern California.

[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 Ocean islands, shorelines, beaches, and coastal plains, through the Transverse and Peninsular Ranges with their peaks, and into the large and small interior valleys, to the vast deserts of California.

[40] California as a whole enacted the Alquist Priolo Special Studies Zone Act in the wake of the 1971 San Fernando earthquake.

The act prohibits new construction of residential buildings closer than 50 feet (15 m) from a surface rupturing active fault zone.

Since 1972, numerous large magnitude earthquakes have struck Southern California with little widespread damage in part due to act.

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.

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.

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 the Bay Area and an emerging Greater Sacramento region.

[49][50] North of Greater Los Angeles are the Santa Barbara, San Luis Obispo, and Bakersfield metropolitan areas.

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.

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.

Locations include: Major professional sports teams in Southern California include: Southern California also is home to a number of popular NCAA sports programs such as the UCLA Bruins, the USC Trojans, and the San Diego State Aztecs.

The Bruins and the Trojans both field football teams in NCAA Division I in the Big Ten Conference, and there is a longtime rivalry between the schools.