25°00′30″S 70°27′53″W / 25.00833°S 70.46472°W / -25.00833; -70.46472

Paposo or Caleta Paposo is a hamlet in the southern part of Antofagasta Province, Chile. It is located on a narrow coastal plain bordering the Pacific Ocean. The census of 2002 counted 259 inhabitants,^[1] who predominantly relied on fishing and mining for a living.^[2] Paposo has a desert climate, but "fog oases" exist on mountain slopes near the sea. In a region almost devoid of vegetation, these oases, also called lomas, support a variety of flora found from about 1 km (0.62 miles) to 4 km (2.5 miles) inland.

Paposo is located adjacent to a cove on the coast of the Pacific Ocean in the Atacama Desert, the driest non-polar desert in the world.^[3] Vegetation is nearly absent in most of the Atacama. The foothills of the Andes rise steeply from the sea, reaching an elevation of 700 metres (2,300 ft) less than 2 kilometres (1.2 miles) from the sea.^[4]

Paposo and the Atacama have the BWn (desert) climate in the Köppen Classification, characterized by mild temperatures, unusual in desert climates, and much fog rolling in from the nearby ocean.^[5] Average temperatures in Paposo range from 13.4 °C (56.1 °F) in July to 20 °C (68 °F) in January, the warmest month.^[6] Annual precipitation is 16 millimetres (0.63 in). July has the most precipitation averaging 4 millimetres (0.16 in).^[7]

The climatic feature which permits the growth of vegetation on the slopes of the mountains rising above Paposo is the Garua or Camanchaca -- cloud banks caused by the cold waters of the ocean. Inland, on mountain sides up to an elevation of 1,000 metres (3,300 ft), the cloud banks form a dense fog which does not produce rain.^[8] The moisture that makes up the clouds measures between 1 and 40 microns across, producing mist and drizzle but too fine to form rain droplets.^[9]