The climate in Argentina is extremely diverse and ranges from tropical in the north to subpolar in the south, with the largest amount of the South American country's population living in the central temperate area. Argentina's 2,295-mile north-to-south length, which stretches as far south as the sub-Antarctic Patagonian Sea, accounts for its climate extremes. The climate differences mostly follow the 1,073,500-square-mile nation's highly contrasted geographic regions.
The Mesopotamia region in the northeast is primarily subtropical, with a hot and humid tropical climate in its northernmost area. The Gran Chaco region is a gently sloping plain to the west that stretches to the Andes Mountain range, and which has a climate similar to Mesopotamia, but with milder and drier winters. The Pampas region is directly south of the Gran Chaco and consists of a vast fertile plain with a temperate climate and cool winters. The climate of the Sierras Pampeanas region is similar to the Pampas, but the terrain consists of medium-high central mountain chains instead of flatland.
The Northwest, Cuyo and Patagonia regions stretch from the nation's northernmost point to its southern tip. Patagonia extends along the southern half of Argentina's north-to-south length. Glaciers and cold winters with heavy snowfalls are part of Patagonia's southern climate with windswept wastes, grasslands and rocky, arid steppes making up the region's northern and eastern areas. The climate is varied, in Argentina's Northwest, with temperatures in the high Andean section often becoming freezing at night, while in the eastern section temperatures are hot and moist. The Cuyo region lies between Patagonia and the Northwest and is generally mild, but in some of its mountainous areas the temperature can remain below freezing throughout much of the year.