Sources: The Library of Congress Country Studies; CIA World Factbook
The Coastal Region
Peru's coast is a bleak, often rocky, and mountainous desert that runs from Chile to Ecuador, punctuated by fifty-two small rivers that descend through steep, arid mountains and empty into the Pacific. The Costa is a strange land of great dunes and rolling expanses of barren sand, at once a desert but with periods of humidity as high as 90 percent in the winter from June to September, when temperatures in Lima average about 16 degrees Celsius. Temperatures along the coast rise near the equator in the north, where the summer can be blazingly hot, and fall to cooler levels in the south. If climatic conditions are right, there can be a sudden burst of delicate plant life at certain places on the lunar-like landscape, made possible by the heavy mist. Normally, however, the mist is only sufficient to dampen the air, and the sand remains bleakly sterile. These conditions greatly favor the preservation of delicate archaeological remains. The environment also facilitates human habitation and housing because the climate is benign and the lack of rain eases the need for water-tight roofing.
The Andean Highlands
For the Peruvians, there are two basic Andean seasons, the rainy winter from October through April and the dry summer in the remaining months. Crops are harvested according to type throughout the year, with potatoes and other native tubers brought in during the middle to late winter and grains during the dry season. The torrential rains of the winter months frequently cause severe landslides and avalanches, called huaycos, throughout the Andean region, damaging irrigation canals, roads, and even destroying villages and cities. In the valley of Callejón de Huaylas, the city of Huaraz (Huarás) was partially destroyed in 1941 by just such a catastrophe, an event repeated a few kilometers away in 1962, when the town of Ranrahirca was annihilated by a huayco that killed about 3,000 people.
The Maritime Region
A maritime region constitutes a fourth significant environment within the Peruvian domain. The waters off the Peruvian coast are swept by the Humboldt (or Peruvian) Current that rises in the frigid Antarctic and runs strongly northward, cooling the arid South American coastline before curving into the central Pacific near the Peru-Ecuador border. Vast shoals of anchovy, tuna, and several varieties of other valued fish are carried in this stream, making it one of the world's richest commercial fisheries. The importance of guano has diminished since the rise of the anchovy fishing industry. The billions of anchovy trapped by modern flotillas of purse seiners guided by spotter planes and electronic sounding devices are turned into fish meal for fertilizer and numerous other industrial uses. Exports of fish meal and fish products are of critical importance for Peru's economy. For this reason, changes in the environmental patterns on the coast or in the adjacent ocean have devastating consequences for employment and, therefore, national stability. The periodic advent of a warm current flowing south, known as El Niño (The Christ-child), and intensive fishing that has temporarily depleted the seemingly boundless stocks of anchovy have caused major difficulties for Peru.
NOTE: The information regarding Peru on this page is re-published from The Library of Congress Country Studies and the CIA World Factbook. No claims are made regarding the accuracy of Peru Climate information contained here. All suggestions for corrections of any errors about Peru Climate should be addressed to the Library of Congress and the CIA.