Peru has three main climate zones: the arid coast, the Andean highlands, and the Amazon basin. Lima is a coastal desert: grey and humid from June to October (16-18°C) with persistent fog (garua), sunny and warm from December to April (25-28°C). Cusco and the Sacred Valley sit at 3,400m with two seasons: dry (May to October) with clear skies and cold nights near 0°C, and wet (November to April) with afternoon rain. The Inca Trail closes in February for maintenance; peak trekking season is June to August. The Amazon (Iquitos, Puerto Maldonado) is hot and humid year-round at 25-33°C with a wetter period from December to May. Lake Titicaca at 3,800m sees intense sun by day and freezing temperatures at night, with the dry season (May to October) offering the most stable conditions.
