Argentina in December: Weather, Crowds & What to Expect
Climate Map for December
Average temperature across Argentina in December.
City Weather in December
| City | High | Low | Rain | UV | Feels |
|---|---|---|---|---|---|
| Buenos Aires | 28° | 17° | 100 mm | extreme | Mild |
| Córdoba, Argentina | 29° | 17° | 157 mm | extreme | Mild |
| Rosario | 29° | 17° | 110 mm | extreme | Mild |
| Mar del Plata | 25° | 13° | 100 mm | extreme | Mild |
| San Miguel de Tucumán | 32° | 19° | 150 mm | extreme | Warm |
| Santa Fe, Argentina | 30° | 18° | 113 mm | extreme | Warm |
| Posadas, Misiones | 32° | 20° | 174 mm | extreme | Warm |
High / low are average daily temperatures (°C). “Feels” reflects how hot or cold it feels, allowing for humidity.
Northwest Andes (Salta, Jujuy, Quebrada de Humahuaca, Cafayate)
December is warm and humid, marking the start of the pronounced wet season: long sunlit mornings often give way to hot, stormy afternoons. This is peak growth time for the valley flora and hotel occupancy rises in popular towns like Salta; the salt flats remain accessible in dry spells but can be flooded after heavy rains. Bring quick-drying clothes, an umbrella for sudden showers, and expect vibrant skies at dusk after storms.
Mesopotamia & Northeast Rainforest (Iguazú, Misiones, Corrientes, Entre Ríos)
December returns the full tropical heat and high humidity, and the rainforest enters its wettest phase with intense afternoon downpours and occasional flooding in lowlands. Iguazú is at its most powerful and photogenic, but visiting trails can be saturated; boat rides may be operated with higher caution. Expect school-holiday crowds; book lodgings early and pack waterproof footwear and repellant.
Cuyo & Mendoza (Mendoza, San Juan, Uco Valley, Aconcagua approach)
December signals full-summer conditions: hot afternoons, lively terraces, and busy vineyards as tourism peaks. Afternoon thunderstorms can punctuate the heat, especially near the mountains, but most days are ideal for al fresco meals and evening strolls through the city. For those planning climbs toward Aconcagua basecamp, acclimatization and careful weather planning become priorities.
Pampas & Buenos Aires (Buenos Aires city, La Plata, Mar del Plata, Rosario, Tigre)
December heats up and humidity returns, reviving the high-season beach vibe along the coast and the city’s outdoor terraces. Storms can be intense and brief; keep an eye on weather apps during long rides and river trips in the Tigre delta. Expect busy travel and higher prices for hotels as both domestic and international visitors arrive to enjoy the summer.
Andean Lake District & Northern Patagonia (Bariloche, San Martín de los Andes, Neuquén, El Bolsón)
December signals full summer - long, warm days interspersed with brisk, windy afternoons; the Lakes district is in high season with lively bars and full bookings. Mountain trails are open and scenic drives are at their best before the Antarctic influence grows in later months; sunscreen, windproofs and a hat are travel essentials. Reserve accommodation and boat trips early for holidays.
Southern Patagonia & Tierra del Fuego (El Calafate, El Chaltén, Ushuaia, Puerto Madryn, Península Valdés)
December is becoming summer-like but remains cooler and much windier than in northern Patagonia; long days are excellent for glacier excursions and for visiting Tierra del Fuego’s trails. Whale-watching continues through the southern spring into early summer and Península Valdés is lively with wildlife; holiday crowds grow around national parks and coastal towns. Bring layered clothing, a warm hat and secure footwear for often-windy shorelines.