Lots of visitors descend on Argentina in December and January, an ideal time to hike in Patagonia, visit the Lake District, or lie on the coastal beaches. But it's not always the best moment to visit Buenos Aires, where temperatures soar and power outages are a perennial problem (or the north interior, where the heat and humidity can be downright intolerable).
The southern hemisphere's winter (June-August) is a good time to visit if you're coming to ski or snowboard - though, ski resorts aside, lots of attractions in the southernmost provinces close down in winter. This is also the best time to visit Salta, Iguazu, and other gorgeous destinations in the north of the country.
Otherwise, the shoulder seasons offer the nicest weather for hiking, sightseeing, wine-tasting, or just lingering over another coffee at a sidewalk café. Harvest time in the wine-growing region of Mendoza starts in March, and the cooler temperatures in the capital make this a great time to visit Buenos Aires, too. From September through November, a colorful burst of flowers and foliage comes to the capital, along with a busy schedule of outdoor fairs and festivals.
With over 3,000 miles of coastline, Argentina is the second-largest country in South America, just behind Brazil. It's therefore difficult to generalize broadly about the regions and climates. But roughly speaking, as far as major tourist destinations go, we can break the country down into the north (including Jujuy, Salta, and Tucumán in the northwest and the Iguazu waterfalls in the northeast), the Andean wine region (Mendoza and San Juan), the central Pampas (including the cities of Córdoba and Buenos Aires) and Patagonia (featuring the Lake District around Bariloche all the way down into Chubut, Santa Cruz, and finally, to Tierra del Fuego.)
December to February (Summer)
Skip the steamy north of Argentina in the summertime and head straight for the lakes, the beaches, and the wide open spaces of Patagonia. True, it's high season for outdoor adventurers who take to the hiking trails in the post-Christmas period, so you'll be paying top prices—and you'll have to plan your accommodations and flights well ahead of time. But you'll benefit from sunny weather and optimal conditions for trekking, biking, camping, rafting, wildlife viewing, and the like.
On any itinerary that takes you to the south of Argentina, it's inevitable that you'll pass through Buenos Aires. Days are long and hot in the capital in January (the average temperature is 76°F (25°C) but most days are much warmer, so it's not the ideal season for exploring the city.
On the other hand, if you don't mind the heat, visitors benefit from the relative peace and quiet in January. Lots of locals leave town, heading to the beach or the mountains for summer vacation. And once the sun goes down, the temperatures drop enough to let you enjoy an al fresco dinner, an outdoor concert, or a bicycle ride around the city.
Autumn (March through May)
Plan ahead, and work up an appetite: this is the best season to visit Argentina's famous wine-growing region. Mendoza is ground zero for wine tasting, wine festivals, and winery tours, plus a wealth of outdoor activities from cycling to horseback riding in the foothills of the Andes. The weather is comfortable, with average temperatures in April rounding out at 63°F (17°C). But if you're looking at unseasonably warm weather, consider driving north from Mendoza to the neighboring province of San Juan. It's less touristy, and the regional specialty is (perfectly chilled) sparkling wine.
Needless to say, this shoulder season is also a great time to visit Buenos Aires. Not only can you count on lovely foliage and perfect weather for full days of walking and sightseeing, but hotel rates typically drop after the busy tourist season of southern hemisphere winter.
Winter (June through August)
Argentina's ski resorts (all located in the south) have been getting more international press than usual in the past year or two. Good for local business, of course, but it could mean more crowds at ski resorts like Chapelco (near San Martín de Los Andes) in upcoming seasons. Argentinian resorts are still under the radar, however, in comparison to their Chilean counterparts on the other side of the Andes.
Bundle up: temperatures hover in the low 30s on the Fahrenheit scale (single digits in Celsius) around Ushuaia, the southernmost city in the world and gateway to the world-class ski area around Cerro Castor. Perhaps more importantly, Patagonian destinations are said to experience all four seasons in the course of a single day, so be prepared to dress in layers.
Outside of the ski centers, many tourist destinations in the south close down in the winter. But it's the perfect time to visit the north, where sunshine and comfortable temperatures make Salta and the nearby wine region of Cafayate particularly welcoming.
Spring (September through November)
Our pick for any visit to Argentina. A bold claim, but consider this: the city of Buenos Aires is a vision in lilac as jacaranda trees bloom left and right, outdoor festivals enliven the city's cultural scene, and the temperatures average around 21°C or 70°F. Meanwhile, the beaches on the Atlantic coast are pleasant but not packed, Patagonia and its parks have re-opened for business, and it's not yet oppressively hot in the north. True, it's not the wine harvest season. But Mendoza is gorgeous in spring as the snowcaps on the Andes start to melt and the rivers rush with icy water.
You heard it here: Argentina is a gem of a destination in all seasons. But spring is really the best.