The climate of Peru is influenced by the cold Humboldt Current, which flows along the Peruvian coast and cools the winds coming from the sea.
LIMA has a mean annual temperature of 18°C. The highest temperatures are reached in the months of January and February, at 31°C. The coldest months are usually from July to September. During this time the thermometer can drop to 11°C.
THE COSTA/coast is low in rain. The average rainfall here is only 40 mm per year (Lima 40-50 mm, Lobitos 10 mm, Tacna 30 mm). From May to November strong fog and cloud formation occurs, the so-called "Garua" (fog rain). During the rest of the year the weather is warm and sunny. In February the average temperature on the Costa is 23.5°C, in August 16°C.
THE SIERRA with its high and densely populated valleys has a partly temperate, partly cold mountain climate. The average annual temperature is 14°C in the western Andes (Arequipa 2,353 m) and 11°C in the highlands (Cuzco 3,450 m). The temperature differences between day and night are considerable. Precipitation often occurs at high altitudes and in the north. The rainy season, which is the warmest time of the year, lasts from December to April. The snow line here is about 5.000 m.
In the SELVA the average temperature is 26°C (maximum 32°C, minimum 19°C). The amount of precipitation in the Amazonas plain is up to 3,000 mm per year. The rainy season lasts from October to April. The humid tropical climate is determined by the jungle.
The most pleasant travel months are from June to October.