Weather in South America

With just a few exceptions, explained below, South America is a year-round destination. The catch is its size. From Santa Marta on Colombia’s Caribbean coast, at 11° north, to Ushuaia on Tierra del Fuego, at almost 55° south, it crosses more than 60 degrees of latitude, with Antarctica beyond. So ask where first, then when.

In general, the continent can be grouped into a few weather regions:

• Tropical: most of Brazil, including the Amazon, the Pantanal and Rio de Janeiro, plus Venezuela, the Guianas and the coasts of Ecuador and Colombia.
• Highland: the Andes, the spine of South America from Venezuela and Colombia down to Chile and Argentina.
• Desert: the Pacific coast of Peru and northern Chile, reaching inland to the Atacama Desert, the world’s driest.
• Temperate and subtropical: Uruguay, Paraguay, central Chile and most of Argentina.
• Cool and windy: Patagonia and Tierra del Fuego.

South America weather at a glance

One official station per destination, north to south, from each country’s climate normals as reported to the World Meteorological Organization, mostly 1991–2020; each destination page gives the exact period for its stations.

Read the rain column twice. Santiago gets 76% of its rain from May to August, just when the Peruvian and Bolivian Andes dry out.

What drives South America’s weather

Opposite seasons, and none at the equator

South of the equator, summer runs from December to February and winter from June to August. Near the equator the calendar stops meaning much: Quito’s monthly average moves by less than 2°F (1°C) a year, and Colombians call a rainy spell invierno, winter, whenever it falls. For which months suit which trip, see the best time to visit South America.

Altitude

In the Andes, altitude does what latitude does farther south. Quito averages about 20°F (11°C) cooler than Guayaquil on the coast, and El Alto, above La Paz, freezes on July nights. The sun gets stronger as you climb, about 10 percent more UV per 1,000 meters, the World Health Organization says.

The Andes as a rain wall

On the Pacific side of Peru and northern Chile, a high-pressure system over the South Pacific, the cold Humboldt Current and the Andes stop rain clouds from growing. Arica, on Chile’s desert coast, gets less than a tenth of an inch (2.2 mm) a year. Farther south, Pacific air loses its moisture crossing the mountains: Puerto Montt, on the Chilean side, gets 61.6 inches (1,566 mm) a year, and Bariloche, across the Andes in Argentina, about half that.

El Niño and La Niña

Some years break the averages. An El Niño warms the sea off Peru and brings heavy rain to its north coast and to coastal Ecuador, up to 100 inches (2,540 mm) in six months in the 1982–83 event, according to NOAA. The same El Niño gives Colombia less rain, while La Niña tends to bring Colombia and Peru more. In a strong year, leave some slack in the plan.

The tropical north and the Amazon

Here the temperature hardly moves and the rain keeps the calendar, a different one in each place. Cartagena is dry from January to March and wet from May to November. The Amazon is hot every month. Manaus is wettest from January to April, Iquitos gets at least 5.2 inches (132 mm) in every month, and the Rio Negro at Manaus floods from May to July, after the rain. The Galápagos are warm from January to May, when most of the rain falls, and cooler from June to December.

Peruvian and Bolivian Andes

The driest time in this part of South America is from May to August, when Cusco gets less than a quarter of an inch (4–6 mm) of rain a month, the sun is strong and the nights are cold, 30°F (−1°C) in July. The rains start from September to November and peak from December to March. That season is warmer only at night; Cusco’s afternoons stay at 68–72°F (20–22°C) all year. Machu Picchu, about 2,600 ft (800 m) lower on the Amazon side, stays near 50°F (10°C) at night and gets about three times Cusco’s rain.

Uyuni gets 94 percent of its rain from December to March, and NASA describes how that water can turn the salt flat into a mirror. Our Uyuni and Atacama Desert tour pairs it with the desert.

The desert coast

Lima gets about a quarter of an inch (6 mm) of rain a year, nearly all of it drizzle. Dry is not sunny: a grey cloud deck covers much of Peru’s coast from June to September. Inland, the Atacama is high and dry rather than hot. At Calama the temperature drops 39°F (22°C) from a July afternoon to dawn.

Brazil

Brazil’s weather is warm or hot year-round in the north and along the coast, and the rain runs on two calendars. São Paulo gets 11.5 inches (292 mm) in January and 1.3 inches (32 mm) in August, while Salvador and Recife, on the northeast coast, are wettest between April and July. The exception is the south of the country, which has a real winter: São Joaquim averages July nights of 43°F (6°C). In the Pantanal the rain peaks from December to March, and the flood on the Paraguay River later, between April and July.

The temperate south

Four seasons here, and four ways to spend the rain. Buenos Aires gets it in every season, Montevideo has no dry season, and Santiago is Mediterranean, wet in winter and dry in summer. In the Chaco, Mariscal Estigarribia averages 97°F (36.1°C) on January afternoons. On the Río de la Plata the sudestada, a strong southeast wind, can hold back the river until it floods its shores.

Patagonia and Antarctica

Away from the Atlantic coast, Patagonia is cool all year and, east of the Andes, drier than it looks. Be prepared for wind. In El Calafate it tops 27 mph (43 km/h) on about 20 days a month from November to January, against six or seven in May and July. From June to August the days are short on light: Ushuaia averages about an hour and a half of sunshine a day in June. Pack a windproof layer for a trek like our El Calafate and El Chaltén tour.

At Esperanza base on the Antarctic Peninsula, the temperature hovers around freezing in the Antarctic summer: a December to February day averages 34°F (1.1°C). In late June, at San Martín, south of the Antarctic Circle, the sun does not rise at all.

Pack for the regions on your route, not the month alone, with our South America packing list. If your trip crosses several of these climates, share your dates when you ask about a custom South America trip.