quality:correction, structural:expansion, quality:corruption
Geography

The South is a diverse meteorological region with numerous climatic zones, including temperate, sub-tropical, tropical and arid – though the South generally has a reputation as hot and humid, with long summers and short, mild winters. Most of the South – except for the areas of higher elevations and areas near the western, southern and some northern fringes – fall in the humid subtropical climate zone. Crops grow readily in the South due to its climate consistently providing growing seasons of at least six months before the first frost. Some common environments include bayous and swamplands, the southern pine forests, the warm temperate montane forest of the Appalachians, the savannas of the southern Great Plains, and the subtropical jungle and maritime forests along the Atlantic and Gulf coasts. Unique flora include various species of magnolia, rhododendron, cane, palm, and oak, among others. Fauna of the region is also diverse, encompassing a plethora of amphibian species, reptiles such as the green anole, the venomous cottonmouth snake, and the American alligator, mammals like the American black bear, the swamp rabbit and the nine-banded armadillo, and birds such as the roseate spoonbill and the extinct but symbolic carolina parakeet.

The question of how to define the boundaries and subregions in the South has been the focus of research and debate for centuries. As defined by the United States Census Bureau, the Southern region of the United States includes sixteen states. As of 2010, an estimated 114,555,744 people, or thirty seven percent of all U.S. residents, lived in the South, the nation's most populous region. The Census Bureau defined three smaller divisions:

The Council of State Governments, an organization for communication and coordination between states, includes in its South regional office the states of Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia and West Virginia.

Other terms related to the South include:

Historically, the South was defined as all states south of the 18th century Mason–Dixon line, the Ohio River, and 36°30′ parallel. Newer definitions of the South today are harder to define, due to cultural and sub-regional differences throughout the region; however, definitions usually refer to states that are in the southeastern and south central geographic region of the United States.

Although not included in the Census definition, two U.S. territories located southeast of Florida (Puerto Rico and the U.S. Virgin Islands) are sometimes included as part of the Southern United States. The Federal Aviation Administration includes Puerto Rico and the U.S. Virgin Islands as part of the South, as does the Agricultural Research Service and the U.S. National Park Service.