Peru lies in three landscape zones, each with its own climatic characteristics:
The "Costa", the smallest coastal region in terms of area, is very dry and agriculture is often only possible in river oases. The capital Lima and the Atacama Desert, the driest desert in the world, are also located in this region. Temperatures in the Costa vary between 12 °C in winter and 35 °C in summer.
In the highlands of the Andes, known as the "Sierra", the average temperature at 3,300 metres is only around 11 °C all year round. From October to April, heavy rainfall can occur in this region, which tends to have little rainfall. Cusco and the Inca ruins of Machu Picchu are located in the Sierra.
The "Selva" rainforest region to the east of the Andes makes up the largest part of Peru at around 60 per cent. The Peruvian rainforest is dense and almost impenetrable, with rivers being the only arteries. The average annual temperature in this region is 26 °C and the annual precipitation reaches up to 3,800 mm. The transition from the sierra is smooth, as there is a tropical mountain forest with a milder climate. Peru's largest nature reserve, Pacaya-Samiria, is located in the Selva.