109,073,023 (2008 est.)
|Largest city||Los Angeles (pop. 3,792,621)|
|Largest Metropolitan Area||Greater Los Angeles (pop. 18,081,000, est. 2011)|
The Sun Belt is a region of the United States generally considered to stretch across the Southeast and Southwest (the geographic southern United States). Another rough boundary of the region is the area south of the 36th parallel, north latitude. The main defining feature of the Sun Belt is its warm climate with extended summers and brief, relatively mild winters. Within the Sun Belt areas of the U.S, deserts (Arizona, California, Nevada, New Mexico, and Texas), Mediterranean (California), and humid subtropical (Texas, Louisiana, Mississippi, Alabama, Florida, Georgia, South Carolina, Arkansas, North Carolina, and Tennessee) climates can be found.
The belt has seen substantial population growth since the 1960s due to an influx of people seeking a warm and sunny climate, a surge in retiring baby boomers, and growing economic opportunities. Also, over the past several decades, air conditioning has made it easier for people to deal with the summertime heat in the region. In recent years water shortages, droughts, and drug trafficking near the Mexican border have become a problem in the western region.
The belt comprises the southern tier of the United States including the states of Alabama, Arizona, Florida, Georgia, Louisiana, Mississippi, New Mexico, South Carolina, Tennessee, Texas, roughly half of California (up to Greater Sacramento), and parts of Arkansas, North Carolina, and Nevada. Four of the states — Arizona, California, Florida, and Nevada — are sometimes collectively called the Sand States due to their abundance of either beaches or deserts.
Author and political analyst Kevin Phillips claims to have coined the term "to describe the oil, military, aerospace and retirement country stretching from Florida to California" in his 1969 book The Emerging Republican Party Majority.
The term "Sun Belt" became synonymous with the southern third of the nation in the early 1970s. There was a shift in this period from the previously economically and politically important Midwest and Northeast to the South and West. Factors such as the migration of immigrant workers from Mexico, warmer climate, and a boom in the agriculture industry allowed for the southern third of the United States to grow economically. The climate spurred not only agricultural growth, but also saw many retirees move into retirement communities in the region, especially in Florida and Arizona.
Industries such as aerospace, defense, and oil boomed in the Sun Belt as companies took advantage of the low involvement of labor unions in the south (due to more recent industrialization, 1930s-1950s) and enjoyed the proximity to many U.S. military installations which were major consumers of their products. The oil industry helped propel southern states such as Texas and Louisiana forward, and tourism grew in Florida and southern California as well. In more recent decades high tech and new economy industries have been major drivers of growth in California, Florida, and other parts of the Sun Belt. Texas and California rank among the top five states in the nation with the most number of Fortune 500 companies.
As of 2005, the U.S. Census Bureau projected that approximately 88% of the U.S. population growth between 2000 and 2030 will occur in the Sun Belt. California, Texas, and Florida are each expected to add more than 12 million people during that time, which will make them, by far, the most populous states in America. Arizona, North Carolina, and Georgia are also expected to make major gains. Nevada, Arizona, Florida, and Texas are expected to be the fastest-growing states.
Events leading up to and including the 2008–2009 recession led some to question whether growth projections for the Sun Belt have been overstated. The economic bubble that led to the recession appeared, to some observers, to have been more acute in the Sun Belt than other parts of the country. Additionally, the traditional lure of cheaper labor markets in the region compared to America's older industrial centers has been eroded by overseas outsourcing trends.
One of the greatest threats facing the belt in the coming decades is water shortages. Communities in California are making plans to build multiple desalination plants to supply fresh water and avert near-term crises. Texas, Georgia, and Florida also face increasingly serious shortages because of their rapidly expanding populations.
Lingering effects from the Great Recession slowed down, and in some places even stopped, the migration from the Frost Belt to the Sun Belt, according to data tracking people's movements over the year from July 2012-2013. Americans remained cautious about moving to a different state over this period. 
The environment in the belt is extremely valuable, not only to local and state governments, but to the federal government. Eight of the ten states have extremely high biodiversity (ranging from 3,800 to 6,700 species, not including marine life). The Sun Belt also has the highest number of distinct ecosystems: chaparral, deciduous, desert, grasslands, and tropical rainforest. From the marshes on Florida's mainland to its extensive coral reefs, the state leads the entire nation in terms of its diversity in animal and plant species.
- American crocodile
- Black-footed ferret
- California condor
- Florida panther
- Red-cockaded woodpecker
- Longleaf Pine
Major cities in the Sun Belt
Largest Metropolitan Statistical Areas Principal City Population (2012 est.)
Los Angeles 13.0 $755.0 Dallas 6.7 $401.3 Houston 6.2 $420.4 Miami 5.8 $260.0 Atlanta 5.5 $283.8 San Francisco 4.5 $335.3 San Bernardino 4.4 $111.3 Phoenix 4.3 $194.4 San Diego 3.2 $175.0 Tampa 2.8 $115.2 Charlotte 2.3 $117.8 Orlando 2.2 $105.0 Las Vegas 2.0 $91.8 San Jose 1.9 $182.8 International regions San Diego–Tijuana 5.0 (2009 est.) $176 El Paso–Juárez 2.7 (2012 est.)
The five largest metropolitan statistical areas are the Los Angeles, Dallas, Houston, Miami, and Atlanta metropolitan statistical areas. The Los Angeles area is by far the largest with over 13 million inhabitants as of 2012[update]. The ten largest metropolitan statistical areas are found in the states of California, Texas, Georgia, North Carolina, Florida, and Arizona. Additionally, the cross-border metropolitan areas of San Diego-Tijuana and El Paso-Juárez lie partially within this belt. Seven of the ten largest cities in the United States are located in the Sun Belt: Los Angeles (2), Houston (4), Phoenix (6), San Antonio (7), San Diego (8), Dallas (9), and San Jose (10).
- "State & County QuickFacts". US Census Bureau. Retrieved 2008-07-24.
- Woods, Michael (18 January 1981). "Desert-Like Conditions Hurt Sun Belt". The Blade (Toledo, OH), reprinted by Google News Archive
- Shayna M. Olesiuk and Kathy R. Kalser (2009). "The Sand States: Anatomy of a Perfect Housing-market Storm". FDIC Quarterly 3 (1): 30–32. Retrieved August 4, 2013.
- Phillips, Kevin (2 April 2006). "How the GOP Became God's Own Party". Washington Post. Retrieved 5 September 2012.
- Sun Belt Growth Shapes Housing's Future, Professional Builder, 1 May 2005
- Lewan, Todd: Has economic twilight come to the Sun Belt?, MSNBC, 31 May 2009
- Cetron, Marvin J.; O'Toole, Thomas: Encounters with the future: a forecast of life into the 21st century, Mcgraw-Hill, April 1982, pg. 34
- Shankman, Sabrina: California Gives Desalination Plants a Fresh Look , Wall Street Journal, 10 July 2009
- McGovern, Bernie: Florida Almanac 2007-2008, Pelican Publishing Company, March 2007, pg. 53
- New data show 'snowbelt-to-sunbelt' migration sluggish to return, Los Angeles Times, 2014
- Annual Estimates of the Population of Metropolitan and Micropolitan Statistical Areas, United States Census Bureau, July 2012
- U.S. Metro Economies: Gross Metropolitan Product with Housing Update, The United States Conference of Mayors, July 2012
- Weinstein, Bernard L.; Robert E. Firestine (1978). Regional growth and decline in the United States: the rise of the Sunbelt and the decline of the Northeast. Praeger Publishers. ISBN 9780275239503.
- Hollander, Justin B. (2011). Sunburnt Cities: The Great Recession, Depopulation, and Urban Planning in the American Sunbelt. Taylor & Francis. ISBN 9780415592116.