Lomas, also called fog oases and mist oases, are areas of fog-watered vegetation in the coastal desert of Peru and northern Chile. About 100 lomas near the Pacific Ocean are identified between 5°S and 30°S latitude, a north–south distance of about 2,800 kilometres (1,700 mi). Lomas range in size from a small vegetated area to more than 40,000 hectares and their flora includes many endemic species. Apart from river valleys and the lomas the coastal desert is almost without vegetation. Scholars have described individual lomas as "an island of vegetation in a virtual ocean of desert."
Lomas de Lachay is a protected area north of Lima.
Moisture from the coastal fog condenses into water droplets that permit plants to flourish without rainfall.
A fog oasis at the Atiquipa Lomas, Peru.
Except for the lomas and river valleys the deserts of Chile and Peru are barren.
Garúa is a Spanish word meaning drizzle or mist. Although used in other contexts in the Spanish-speaking world, garúa most importantly refers to the moist cold fog that blankets the coasts of Peru, southern Ecuador, and northern Chile, especially during the southern hemisphere winter. In Chile, a similar fog is called camanchaca. Garúa brings mild temperatures and high humidity to a tropical coastal desert. It also provides moisture from fog and mist to a nearly-rainless region and permits the existence of vegetated fog oases, called lomas.
Garúa in Lomas de Lachay, near Lima, Peru,
Garúa is similar to camanchaca.
Atiquipa, Peru. The moisture from the garúa is sufficient to permit trees to flourish.