🇵🇪Peru

Peru (1,285,216 km²) spans 0°–18°S along South America's Pacific coast, encompassing three distinct climatic regions: the hyperarid coastal desert (Sechura Desert in the north, merging into the Atacama southward), one of Earth's driest deserts with <30 mm annual rainfall, moderated by the cold Humboldt Current producing persistent garúa fog; the Andes highlands rising to Huascarán (Peru's highest peak) with microclimates from temperate to polar and Peru holding about 70% of the world's tropical glaciers including the Quelccaya Ice Cap; and the Amazon basin covering 60% of national territory with tropical rainforest climate (Af/Am) receiving roughly 1,100–3,000 mm annually, while some slopes near Manu National Park may exceed 8,000 mm. Peru is where the El Niño phenomenon got its name, from Peruvian fishermen, for its Christmas-season arrival.

Coastal Lima (12°S, sea level) has August highs of about 19°C with nights near 15°C and February highs of about 28°C with only 16 mm annual rainfall, shrouded in winter garúa fog yielding just 1,230 sunshine hours yearly, fewer than London. Piura (5°S) has August highs of about 28°C with nights near 17°C and February–March highs of 34–35°C with about 120 mm rainfall. Andean Cusco (14°S, 3,406 m) has highs of about 21°C in July and 22°C in November, with July nights near 1°C and November nights near 8°C, and about 700 mm rainfall concentrated October–April.

Peru experiences significant El Niño-driven climate impacts. The 2017 Coastal El Niño event (the worst since 1925) produced 113 deaths, generated 300 mm daily rainfall in Piura (three times the annual average), and triggered major landslides. The March 2023 Cyclone Yaku killed at least 8 people, affected 49,000, caused $690 million in damage across Peru and Ecuador, and brought rainfall amounts not seen since the 1997–98 and 2017 El Niño events.

Andean glaciers continue to retreat, with the Quelccaya Ice Cap losing 30 percent of its area between 1979 and 2014 and widespread glacier decline across the Peruvian Andes. The 31 May 1970 Ancash earthquake (magnitude 7.9), which killed approximately 66,000–70,000 people, triggered a debris avalanche from Huascarán that buried Yungay and Ranrahirca.

Our archive covers 20 Peruvian cities with daily ERA5 reanalysis data going back to 1940. The hottest July afternoons are in Pucallpa, with average highs around 29.4°C, while Juliaca has the coldest January nights, with average lows near 5.2°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1°C.