On the coast, the climate is mild, and it hardly ever rains. The hottest months are between December and February, when the temperature reaches 28ºC or 29ºC (84ºF). The coldest months are July and August, when the temperature ranges between 13ºC and 19ºC (55ºF to 66ºF) with is a persistent mist, particularly in Lima and the central coast, which dissipates towards the northern coast. The climate is warmer from Trujillo onwards and in Piura and Tumbes one can even bathe in the sea in those months. The weather also improves inland to 600 meters above sea level, half an hour from Lima.
The Sierra region is dry and sunny all year round, although the nights are cool - the higher the altitude, the colder the temperature. Arequipa seems to have an eternal mild summer, whereas in Cusco the air is much cooler. The coldest weather is in Puno, because it is at a higher altitude. The ideal months for visiting the Sierra are between May and October, as the rainy season is from December to March and even though these are the warmest months (19º - 25ºC, 66º-77ºF) when the fields are always green and the sun shines most of the day, avalanches can make traveling by road difficult.
The Jungle region is always very hot, 30ºC (86ºF)in August and about 35ºC (95ºF) between December and April. It rains all year round, although sometimes they are only brief showers. Peru can be visited throughout the year due to its pleasant climate in the various regions.