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Peru Climate, Climate in Peru

Climate in Peru

Peru is a country of varied climate (see also Peru Weather) because the influence of the following phenomena:

The Andes Mountain Range:

On this page:

Climate Factors

The Andes
Peru Current
El Nino
South Pacific Anticyclone
South Atlantic Anticyclone
Equatorial Cyclone

Climate Zones

Coastal
Mountains
Jungle

Traveling the country lengthwise and dividing air masses from the Pacific and Atlantic, this high mountain backbone creates a barrier to the movement of the winds and might be considered the major geological factor affecting Peru climate.

The Peruvian Oceanic Flow (the cold Peru Current):

About 200 km wide, flowing from south to north just off the coast , is a large mass of cold water. This current cools the air. Because such cool air cannot hold much moisture, little rain falls in the region (includes Lima, capital of Peru).

So, while leading to stable atmostpheric conditions, the result is also a lack of rain on the coast of Peru. In fact, southern coastal Peru is one of the driest places on earth.

At irregular periods, usually every two to seven years, the northward Peru Current weakens and the El Nino current of the equatorial zone with its warm waters flows southward along the coast. This can have a powerful effect on the climate in Peru, especially of Northern Peru.

The El Nino:

The El Nino ("the child" in Spanish) phenomenon usually occurs around Christmas, and so the name, referring to the Christ child.

El Nino creates changes in the atmosphere that lead to torrential downpours in the usually dry region, upsetting the normal Peru climate.

In 1998, the El Nino phenomenon dumped tons of rain on the dry Sechura desert in Northern Peru. The result? The second largest lake in Peru, measuring 90 miles [145 kilometers] long and 20 miles [30 kilometers] wide but only an average of 10 feet deep.

The changes caused by the El Nino can also disrupt marine life and have had a very negative effect on the local fishing industry. This is really noticeable in the town where we live, Los Organos, where previously many people were employed mainly in the giant squid fisheries but are now out of work.

Definitions

Cyclone: An area of closed, circular fluid motion rotating in the same direction as the Earth[1][2]. This is usually characterized by inward spiraling winds that rotate counter clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere of the Earth. Most large-scale cyclonic circulations are centered on areas of low atmospheric pressure.

Anticyclone: An anticyclone (that is, opposite to a cyclone) is a weather phenomenon defined by the National Weather Service's glossary as "A large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere, anticlockwise in the Southern Hemisphere".

The South Pacific Anticyclone:

This is a high pressure system with wind movement from south to north that collects moisture and takes it to the coast. The climate in Peru along the coast is a result of this air mass plus other factors such as the Peru Current (or Humbolt Current). Although not enough to bring rain, the moisture often condenses into clouds or fog. This brings the persistent cloudy weather in most of Coastal Peru from May to October with a somewhat high atmospheric humidity.

The South Atlantic Anticyclone:

Situated near the Argentinean coast, this consists of humid air masses which affect southeast Peru, causing rain in the southern Andean flank.

Between May and September, Peru climate sudden drops in temperature as this frigid air mass moves north. These cold fronts, lasting one or more days, are known as "surazos" or "big southerns."

The Equatorial

Located in the Amazon basin, this is a huge low pressure air mass. The air is warm and moist and the result is the large amount of rainfall and warm weather on the forest floor.

These are the factors that create the huge diversity in Peru climate zones, and the overall climate in Peru.

Peru Climate Zones:

La Costa (The Coast)

* General Coastal Peru Climate: Weather semiwarm and very dry or desert with very little rainfall, about 150 mm (5.9 inches) per year. This involves the coast from sea level to 2,000 meters (6,600 feet) and is characteristically barren.

* Northern Coastal Peru Climate: Very dry warm climate on the northern coast (Piura and Tumbes) and up to about 1,000 meters (3,300 feet.) Dry with low rainfall of 200 mm (8 inches) per year, and temperatures average 24 degrees C (75 F).

Sierra (Mountains)

* Temperate sub-humid: In the mountains between 1,000 and 3,000 meters, with temperatures around 20 degrees C (60 F) and rainfall between 500 and 1,200 mm (20 to 42 inches) per year.

* Cold Climate: Typical of the Andean valleys between 3,000 and 4,000 meters. The average rainfall is 700 mm (28 inches) per year and average temperatures around 12 degrees C (53 F) down to freezing during the winter.

* Weather frigid or 'puna': Between 4,000 and 5,000 meters. With average rainfall of 700 mm (28 inches) and average temperatures of 6 degrees C (43 F). Summers are rainy and winters are dry.

* Snow or icy Weather: Above 5,000 meters with temperatures below 0 degrees C (32 F). This Peru climate is found in the high peaks with snow.

Selva (Jungle)

* Mid warm humid climate: On the eastern slopes of the Andes, rainfall is about 2,000 mm (79 inches) per year and temperatures below 22 degrees C (72 F). There are local variations.

* Weather warm tropical moist or wet: Predominates in the lowland rainforest (see Iquitos, upper Amazon). The rainfall is around 2,000 mm (79 inches) per year, and temperatures average 25 degrees C (75 F) with extremes above 30 degrees C (86 F).

The variety in Peru climate allows for high biodiversity and production.

Go from Peru Climate to Peru Weather for more information and current weather conditions in Peru.