Weather in Peru is varies from region to region, according to the World Meteorological Organization Peru enjoys 28 out of the 32 world climates. Two main factors contribute to the variety of climates, the Andean Mountain Range and the Humboldt Current. However, climate in Peru can generally be divided in three different climatic zones: the coastal desert that borders the Pacific Ocean to the West, the Amazonia or rainforest to the east and the Andes in between the coast and the rainforest. There are many microclimates within each region.
The average temperature from December to April is 25 to 28C or 53 to 59F and the average temperature from May to November is 12 to 15C or 53 to 59F. Lima and other cities along the coast during the winter months –May to November- is covered with a thick fog or mist called garua that prevents the sun from penetrating and everything looks gray. This is the effect of the Humboldt Current. When the cold air of the Pacific Ocean comes in contact with the warmer air from the desert, it forms a thick fog that lingers during the winter months and creates different microclimates along the Pacific Coast. However, in the north coast the climate remains hot year round.
Climate in the coast of Peru is also affected by El Niño and La Niña which bring warm and cold water respectively to the Western Pacific Ocean and occurs on average every five to seven years. Its name refers to “the child Christ” as the warming of the ocean is noticed around Christmas. This phenomenon causes floods, droughts and destruction.
Tables of monthly temperature and rainfall for the coastal cities of:
Climate in the Andes or Sierra region depends on the altitude. There are many microclimates in the Andean mountain chain. The higher you go the colder, drier and less oxygen you get. When you travel to the Andes you need sometime to acclimatize to the altitude due to the exposure of low pressure of oxygen. Some people get affected by altitude sickness or soroche which usually occurs at altitudes above 2,400 or 8,000 feet.
There are two well defined seasons throughout the year: the dry and the rainy seasons. The dry season is between April and October with sunny days and cool nights. The rainy season is between November and March, the amount of precipitation and the temperature vary according to the altitude.
Tables of monthly temperature and rainfall for the Andean cities of:
In the rainforest the sun always shines except when it rains, but it rarely rains for more than a few hours at a time.
The tropical rain forest is swampy, humid and hot, its yearly rainfall stands at 103 in or 262 cm. The average high temperature is 100F or 37.7C and the low average temperature is 59F or 15C. The rain season runs from December through April.
Table of monthly temperature for the rainforest city of: