South America in December: Weather, Crowds & What to Expect

Caribbean Coast & the Guianas (Venezuela’s northern coast, Guyana, Suriname, French Guiana)

This is the driest, sunniest stretch of the year with daytime temperatures in the high 20s to low 30s and comfortable coastal breezes; it’s the high season for beach resorts and city breaks. Carnival build-up in towns like Caracas may start later, and flights and hotels can fill quickly from mid-December onward, so reserve early if you want popular seaside hotels. The Guianas are pleasantly dry for river travel and outdoor dining; still carry sunscreen and a hat for unrelenting equatorial sun.

Amazon Basin (Brazilian Amazon, eastern Peru, southern Colombia, Ecuador, Bolivia)

The basin is mostly in its dry phase with sunny early days and warm afternoons; daytime thermometers typically read 27-31°C and humidity is noticeably lower. Boat operations are reliable and many research stations and lodges schedule their busiest windows, so expect more visitors at popular reserves. This is an excellent month for combining river cruises, canopy platforms and guided hikes-pack breathable layers, sturdy boots and good sunscreen.

Northeast Brazil & the Sertão (Coastal cities: Salvador, Recife, Fortaleza - interior drylands of the Sertão)

A gradual easing of intense interior drought can be seen in many areas as the rainy season either tapers or becomes more regular; coastal cities enjoy warm sea temperatures and balmy evenings at around 28-31°C. The sertão can go through short dry spells between storm cycles, so expect a mix of green pulses and dusty stretches-flexibility helps. This is a shoulder period for tourism: fewer crowds than Carnival season but good value and active local festivals.

Southeast Brazil & Central Plateau (Rio de Janeiro, São Paulo, Minas Gerais, Brasília, Goiás)

Rainfall is low across the central plateau and decreases along the coast, which often yields long, comfortable days for sightseeing in Rio, São Paulo and Belo Horizonte. Temperatures are mild to warm-daytime highs usually in the low to mid-20s inland and slightly warmer at the coast-making it a popular time for urban exploration and wine-region visits. Book ahead for spring festivals and bring a light sweater for cooler nights.

Andean Highlands & Altiplano (Colombia highlands, Ecuador, Peru highlands, Bolivia’s Altiplano, northern Argentina high Andes)

Clear, dry air dominates and this is one of the most reliable months for high-elevation travel-treks, mountain climbs and archaeological visits run at full capacity. Daytime warmth on terraces offsets frosty nights; sunny mornings are excellent for photography and panoramic vistas. Expect higher visitor numbers on marquee routes and secure permits and guides early; layers for temperature swings and proper acclimatisation remain non-negotiable.

Northern & Central Chile - Atacama, Coastal North and Central Chile (Arica to Santiago, including Atacama Desert and valleys)

Northern deserts maintain warmth by day and exceptional clarity at night, while central Chile moves into its coolest, damptest months with periodic rain in Santiago and coastal towns. Ski season begins in the nearby Andes, with Valle Nevado and Portillo opening under good snow conditions-this is the regional winter for mountain sports. For desert tour operators the steady, cold nights continue to favour stargazing and salt-flat photography.

Patagonia & Tierra del Fuego (Southern Chile & Argentina: Chiloé, Puerto Montt, Torres del Paine, Ushuaia, southern Lake District)

Shoulder-season variability continues with a mix of clear, cool days and sudden wet spells; daytime temperatures become milder and daylight grows noticeably longer. Spring reveals new greenery and some operators reopen for full summer schedules-this is a good time for quieter visits before the main season. Always plan for wind and expect last-minute cancellations on small private boat trips in fjords and channels.