Climate of Peru

The climate of Peru is very interesting because this large country in South America has many different kinds of weather. Peru is found in a warm part of the world called the tropics, but it has deserts, mountains, and tropical rainforests too. The land in Peru goes from very low, even below sea level, up to very high mountains, so the weather changes a lot depending on where you are.

Along the Pacific Ocean coast, Peru has one of the driest deserts on Earth, but it still has some special weather patterns. In the high Andes mountains, the climate changes with height and direction, with temperatures ranging from mild to very cold and weather from dry to very wet. In the Amazon basin, the climate is usually tropical with lots of rain, but in some higher areas, it can be more like a sub-tropical climate.

Pacific coastal desert

The coastal desert of Peru stretches from near the border with Ecuador all the way to the border with Chile. This desert is divided into three parts: the Sechura Desert in the north, the Peruvian coastal desert in the middle, and the Atacama Desert in the south.

Even though Peru is close to the equator, this desert stays cool because of the cold Humboldt Current in the ocean. This current brings in fog called garúa, especially during the cooler months. The fog helps keep the air very moist, making places like Lima quite cloudy and not very sunny. Inland, as the land rises, more rain falls, allowing some plants to grow in special areas called lomas.

Andean highlands

See also: Rainy season in the Altiplano

The Andes mountains cover a big part of Peru, stretching from north to south. These mountains are very high, with most areas above 2,000 meters (6,600 feet) and many parts even higher than 3,000 meters (9,800 feet). The western sides of these mountains, facing the Pacific Ocean, are drier, while the eastern sides are wetter. There are many snowy and icy peaks that rise above 5,000 meters (16,000 feet), and thirty-seven mountains in Peru reach even higher than 6,000 meters (20,000 feet).

In mountainous areas, the temperature gets colder the higher you go. Generally, it drops by about 6.5 °C for every 1,000 meters you climb. The steep and changing landscape creates many tiny climates, where moving just a few kilometers can change the weather a lot. The Andes have a rainy season from October to April and a dry season from May to September. Snow is common above 3,800 meters (12,500 feet). The city of Puno gets snow about 14 days each year and can have freezing temperatures almost every morning.

The indigenous peoples of Peru have lived and farmed in the Andes for thousands of years, even with the tough weather. They use special farming methods like andenes (terraces) and Waru Waru (raised beds) to help grow crops such as potatoes up to high elevations. Animals like llamas and alpacas graze in the puna zone, which is a high, grassy area up to about 4,770 meters (15,650 feet).

Amazon rainforest

The Amazon rainforest covers about 60 percent of Peru. It has hot temperatures all year with lots of rain. There are three types of tropical climates here, but they are very similar. The true rainforest climate needs at least 60 mm of rain every month.

The Amazon and mountain climates meet at higher elevations, where it gets cooler. Around 1,550 meters, the climate becomes milder, often called "eternal spring," with temperatures between 11°C and 26°C and rain all year. Some places at similar heights have a dry season.

Quince Mil gets the most rain in Peru, but some mountain slopes in Manu National Park might get even more than 8,000 mm of rain each year.

El Niño

El Niño and La Niña are parts of a weather pattern called the El Niño–Southern Oscillation. They change weather around the world, especially near the coasts of northern Peru and southern Ecuador. El Niño happens every two to seven years. During this time, ocean temperatures near Peru's coast get warmer, sometimes by up to 3°C (5.4°F), usually around Christmas. This name comes from the birth of Jesus.

When El Niño happens, the coasts of Peru get warmer and sunnier weather. In strong years, like 1982–1983, 1997–1998, and 2015–2017, it brings a lot of rain to areas that are usually very dry. This can cause floods and landslides called huaycos. The warmer water also makes it harder for fish to live, and the southern Andes mountains get less rain than normal.

Climate change

The climate in Peru is changing, and this affects many parts of the country. From 1960 to 2016, average temperatures rose by about 1°C (1.8°F), and they are expected to rise even more in the future. This warming can lead to more extreme weather, like droughts and floods.

One big problem in Peru is the melting of glaciers in the Andes mountains. Peru has many of the world's tropical glaciers, and they have been shrinking since 1970. This melting changes the amount of water available, causing floods in wet seasons and less water in dry seasons. Many people and farms depend on this water, so changes in glaciers can cause big problems.

Peru has created plans to study and respond to climate change, aiming to protect its people and natural resources. The country hosted an important international meeting on climate change in 2014 and has laws to better manage greenhouse gases.