Weather
The onset of autumn in Argentina brings slightly cooler temperatures and the start of fall foliage, though this varies by location. The northern part of the country is still warm, while the central part of the country is more temperate—a great time to see wildflowers, changing fall leaves, and the start of harvest festivals in Argentina's wine country. Buenos Aires, for instance, sees average highs in the upper 70s Fahrenheit and lows in the mid-60s with slightly more rain in March.
The farther south you travel, the more extreme the weather conditions become. Some areas of Patagonia become totally inaccessible in winter months, so going now—during the beginning of shoulder season—is a smart move, especially after the summer winds die down. Ushuaia, Patagonia's southernmost city, sees highs in the mid-50s and lows in the 40s during March. Wherever you go, it's best to pack plenty of layers and outdoor weather gear in case of rain.
Crowds & Costs
March is a bit of a transitional month, with summertime tourists thinning out by mid-month. Traveling during the beginning of this autumn shoulder season means better prices and fewer international tourists in places like Buenos Aires and Patagonia. Locals also get back into their routines after their February vacations, making the beaches and Bariloche (Lake District) less crowded as well. Mendoza, however, will see a spike in crowds and prices at the annual Grape Harvest Festival (more below).
Where to Go
You can't go wrong choosing destinations in Argentina this time of year. This is still a good month for hiking in Patagonia's Los Glaciares National Park (if you don't mind the occasional bout of rain), and it's also the best season to visit Argentina's famous wine-growing region. Mendoza is ground zero for wine tasting, wine festivals, and winery tours, plus outdoor activities from cycling to horseback riding in the foothills of the Andes. 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.
This is also a great time to head to Iguazú National Park, where hundreds of cascading waterfalls make up the park's main attraction: crowding out to the end of the viewing platforms to get a look at one of the largest, widest, and mightiest series of cascades anywhere in the world, and then returning. Shoulder season is also a great time to visit Buenos Aires. You can count on changing, nice early-autumn weather for full days of walking and sightseeing.
Chat with a local specialist who can help organize your trip.
What to Do
There are plenty of activities, both relaxing and active, to consider in Argentina during March. Los Glaciares offers spectacular day hikes in and around Mount Fitz Roy that are accessible from El Chaltén. The national park also offers a number of guided multiday trekking opportunities while camping overnight. You'll also have access to Perito Moreno, one of the few advancing (rather than retreating) glaciers in the world, where you can choose among several scenic boat tours; better yet, go ice trekking with a guide while avoiding the tourists.
While in Patagonia, consider visiting Península Valdés, a peninsula near Puerto Madryn. Nearly 100,000 visitors make their way here each year to experience South America's most varied marine life, including the southern right whales, Magellanic penguins, sea lions, and elephant seals.
North in Iguazú Falls, you can get up to the waterfalls by bike instead of boat. In fact, Puerto Iguazú is renowned for its almost exclusively off-road red-dirt tracks that wind through the jungle toward the waterfalls, offering a unique experience often missed by tourists.
Events in March
Grape Harvest Festival, Mendoza. In honor of wines from throughout the region, Mendoza holds a weeklong Fiesta Nacional de la Vendimia in March, which kicks off with parades, folk events, and the royal coronation of the queens chosen by Mendoza's districts. For wine enthusiasts, this is the biggest party of the year in Argentina's most prestigious wine-making region.
Holy Week, Nationwide. Easter week tends to fall in April, so check out next month's "Events in April" for more information about festivities in Argentina.
Traveling to Argentina in March? Check out these great itineraries
Patagonia Wilderness Excursion - 15 Days. Starting in Buenos Aires, you'll get up close to massive glaciers, sail the pristine channels and fjords on a multiday cruise, and enjoy the magnitude of Patagonia's most famous—and therefore scenic—national parks. Mixing relaxation and adrenaline, the tours are flexible for those who prefer more (or less) challenging activities.
Buenos Aires & Iguazú Falls - 9 Days. Kick off in Buenos Aires, where you'll explore neoclassical architecture, buzzing neighborhoods, and urban escapes by foot, boat, and bicycle. Next, fly north to the Brazilian border to experience hundreds of waterfalls in both countries. Circle back to the big city for a tango performance to complete the adventure.
More Helpful Information
Argentina in February
Argentina in April
Best Time to Visit Argentina
How Many Days to Spend in Argentina