Earth Processes · Peru
Climate, Biomes
& Change
One country, three worlds — the geography that has made Peru one of the most biodiverse regions on the planet.
“Peru’s location in the tropics, flanked by the Andes and the cold Pacific Ocean, creates a unique blend of climates, ecosystems, and forms of life found nowhere else on Earth.”
Geography
One country, three worlds
The Andes act as a monumental climatic barrier. Their presence physically separates three radically different regions: the arid western coast, the cold and rugged highlands, and the humid Amazon rainforest.
Coast
Arid desert · Humboldt Current
Mountains
Cold highlands · Tropical glaciers
Jungle
Amazon · Rain all year round
Climate Controls
The three factors that define Peru’s climate
Wind Patterns and Circulation Cells
Peru lies within the convergence zone of the Hadley cell, where tropical air rises at the equator and sinks in the tropics, creating arid areas along the coast. The easterly trade winds carry moisture from the Atlantic toward the Amazon region.
Precipitation — From the Desert to the Rainforest
Rainfall varies dramatically across Peru. The coast receives almost no rainfall at all each year due to the temperature inversion caused by the Humboldt Current. The high jungle, however, can receive over 6,000 mm of rain annually, making it one of the rainiest regions on the planet.
Extreme Climates — From the Arctic to the Tropics
In a single day of travel, you can experience climates that are separated by thousands of kilometers in the rest of the world: from the humid heat of the Amazon to the freezing cold of Mount Huascarán (–20°C), passing through the coastal desert.
Climate Classification
Köppen Climate Zones of Peru
Peru spans more than 80 distinct microclimates. The Köppen–Geiger classification system identifies six major climate types across the country’s three geographic regions — each one shaped by altitude, ocean currents, and the barrier of the Andes.
Pacific Coast
BWh
Hot Desert
The Humboldt Current chills the coastal air, creating a temperature inversion that suppresses rainfall. Annual precipitation is often below 50 mm — yet temperatures remain mild rather than scorching, unlike most deserts at this latitude.
Amazon Lowlands
Af
Tropical Rainforest
Covering roughly 60% of Peru, the Amazon basin receives abundant rainfall year-round. High humidity and temperatures averaging 25–30°C support the planet’s most biodiverse terrestrial ecosystem.
Andean Mid-Elevations (2,000–4,000 m)
Cfb / Cwb
Temperate Highland
Cities like Cusco fall here — mild summers, dry winters, and dramatic temperature swings between day and night. Wet season runs November–April, driven by moisture transported from the Amazon.
High Puna (above 4,000 m)
ET
Tundra
Frost occurs in every month of the year at these elevations. The puna grassland ecosystem has adapted to this harsh cold, supporting camelids like vicuñas and alpacas that graze on ichu grass.
Glaciated Peaks (above 5,000 m)
EF
Ice Cap
Peru holds 71% of the world’s tropical glaciers. Peaks like Huascarán (6,768 m) remain permanently frozen. These glaciers are rapidly retreating — a critical visible indicator of climate change in the region.
Andean Rain-Shadow Valleys
BWk / BSk
Cold Desert / Steppe
Western Andean valleys like those near Arequipa sit in the rain shadow of the mountains. They receive far less moisture than the eastern slopes, producing cold desert and semi-arid steppe conditions.
Biomes
The big three
Click on each strip to explore the biome and its contribution to Peruvian society.
Biomes & Society
Do Peru’s biomes unite or divide its people?
A history of division
For most of Peru’s history, its three great biomes acted as walls rather than bridges. The Andes physically separated coastal civilizations from Amazonian peoples, making trade, communication, and political unity extraordinarily difficult. Even after independence in 1821, Lima — a coastal city — concentrated political and economic power while the highland and jungle regions remained marginalized.
This geographic inequality persists today. Indigenous Andean and Amazonian communities frequently lack access to the same infrastructure, healthcare, and economic opportunity available on the coast. During disasters like El Niño flooding, it is rural highland and jungle populations who suffer most and receive the least aid. The country’s geography did not create inequality, but it has always made it easier to ignore.
A growing source of identity
In recent decades, Peru’s extraordinary biodiversity has become a powerful source of national pride and cultural unity. The phrase “un país de tres mundos” — a country of three worlds — is taught in schools and celebrated in tourism campaigns. Peruvians across all regions increasingly identify with the richness that their geographic diversity produces: from Andean quinoa and Amazon cacao to Pacific seafood that defines world-renowned Peruvian cuisine.
Environmental movements have also brought coastal, Andean, and Amazonian communities together around shared concerns — particularly the defense of glacier water sources and opposition to deforestation. Indigenous rights groups from the Amazon have gained national and international visibility, reshaping how Peru understands its ecological and cultural heritage.
“Peru’s biomes have long divided its people by making geography an obstacle to equality — but they are increasingly uniting Peruvians around a shared identity built on the remarkable diversity of the land itself.”
— Author’s analysis
Featured Video
Peru’s Living World
The following video shows the experience from an explorer showing Peru’s Amazon rainforest. It illustrates many of the ecosystems, species, and climate pressures discussed on this page.
Flora
Plants native to Peru
Unique species that have coevolved with their ecosystems over millions of years.
Fauna
Animals native to Peru
Icons of Peru’s biodiversity, unique to their ecosystems.
“Peru is one of the 17 megadiverse countries on the planet—those that together are home to more than 70% of the Earth’s terrestrial biodiversity.”
— UNEP Conservation Monitoring Centre —