How we know: Sources are listed at the end. Weather figures are official climate normals; route facts come from airline pages. Wildly does not publish fare averages in prose; live prices are on the linked route pages.
Argentina runs roughly 2,300 miles from subtropical Iguazú Falls to the glaciers of Patagonia, so the "best time" depends on where you are going. For a trip built around Buenos Aires, Mendoza wine country and the northwest, autumn (April–May) and spring (September–November) give the most comfortable weather and sit outside the southern-hemisphere summer holiday peak. For Patagonia trekking you are tied to the November–March season no matter what fares do.
Buenos Aires weather by month
Official 1991–2020 climate normals for Buenos Aires Central Observatory, published by Argentina's Servicio Meteorológico Nacional (SMN):
| Month | Avg high | Avg low | Rain | |---|---|---|---| | January | 86°F (30°C) | 68°F (20°C) | 5.3 in | | February | 84°F (29°C) | 67°F (19°C) | 5.1 in | | March | 81°F (27°C) | 64°F (18°C) | 4.7 in | | April | 74°F (23°C) | 57°F (14°C) | 5.1 in | | May | 67°F (19°C) | 52°F (11°C) | 3.7 in | | June | 62°F (16°C) | 47°F (8°C) | 2.4 in | | July | 60°F (16°C) | 46°F (8°C) | 2.9 in | | August | 64°F (18°C) | 48°F (9°C) | 2.8 in | | September | 67°F (20°C) | 51°F (11°C) | 3.2 in | | October | 73°F (23°C) | 56°F (13°C) | 4.8 in | | November | 79°F (26°C) | 61°F (16°C) | 4.6 in | | December | 84°F (29°C) | 65°F (19°C) | 4.8 in |
January is the hottest and wettest month; June–August are the driest. April–May and September–October land in the comfortable 65–75°F range with moderate rain, which is why they are the usual recommendation for city-focused trips.
Season by season
December–February (summer, peak). Hot and humid in Buenos Aires, and the whole country travels domestically over the January holidays. This is the reliable window for Patagonia (El Calafate, El Chaltén, Torres del Paine across the Chilean border) and Iguazú runs at high flow, but coastal and Patagonian lodging is at its busiest.
March–May (autumn). Temperatures fall from the low 80s to the high 60s, Mendoza's grape harvest runs in March, and crowds thin after Easter. Patagonia services wind down through April. May is the sweet spot for Buenos Aires, wine country and the Salta region.
June–August (winter). Buenos Aires is mild and grey (highs around 60°F); Bariloche ski season runs in this window; most Patagonia trekking infrastructure is closed. Fewer visitors overall.
September–November (spring). Jacarandas bloom in Buenos Aires in November, temperatures climb back through the 70s, and Patagonia lodges reopen through October and November. Early November, before the December holiday run-up, is a good compromise if you want both the capital and the far south.
Getting there from the US
Buenos Aires Ezeiza (EZE) is the international gateway. American Airlines lists Buenos Aires service with nonstop and connecting options from a long list of US cities, with Miami, New York (JFK), and Dallas–Fort Worth the core gateways; other US departures usually connect through one of those hubs or through Lima, Bogotá, Panama City or Santiago. Aerolíneas Argentinas, Delta and United also serve EZE from the US; check each carrier's schedule for the season you are travelling because some services are seasonal.
Flying time from Miami is roughly 9 hours; from New York about 11; from the West Coast expect a connection and a 14-hour-plus journey.
For current fares on the main gateways see JFK to Buenos Aires, Miami to Buenos Aires and LAX to Buenos Aires. Those pages show what the route is actually pricing at today, which is more useful than a seasonal average.
When fares tend to be lowest
Demand on US–Argentina routes follows the southern-hemisphere holiday calendar: the December–February summer peak and the northern-hemisphere Christmas period overlap, and that is when published fares are usually highest. Autumn and the winter months are the quieter periods. Rather than trusting a rule of thumb, set a price alert on your route with a target price and let the fare come to you; the route pages above show recent prices so you can pick a realistic target.
Entry requirements for US citizens
US passport holders can enter Argentina for tourism without a visa for stays of up to 90 days (Wikivoyage, "Get in"). Bring a passport valid for the length of your stay and proof of onward travel; requirements can change, so confirm with the Argentine consulate before you fly.
Where to go, by month
- April–May: Buenos Aires, Mendoza (post-harvest), Salta and the Quebrada de Humahuaca, Iguazú at moderate flow and lower humidity.
- June–August: Buenos Aires museums, theatre and tango; Bariloche for skiing; day trip by ferry to Colonia del Sacramento, Uruguay.
- September–November: Buenos Aires in bloom, Mendoza warming up, Patagonia reopening late in the window.
- December–February: Go south. Patagonia, the Lakes District and Ushuaia are at their best while the capital is at its hottest.
Most first-time visitors do well with Buenos Aires (3–4 nights) plus one secondary region rather than trying to cover the whole country in ten days.
FAQ
Is Argentina expensive for Americans? Generally cheaper than Western Europe for food and lodging, though prices in dollars move quickly with the exchange rate. Check recent traveller reports close to your dates rather than relying on year-old figures.
How many days do you need? At least seven or eight given the flight time. Buenos Aires plus one other region is the realistic scope for a week.
Can you visit Patagonia year-round? Not in practice. Most lodges and trekking operators run roughly November through March or April; El Calafate keeps some glacier tours going in winter, but El Chaltén largely closes.
What is the best month for Iguazú Falls? Flow is highest in the December–April rainy season, when it is also hottest. May and September trade some volume for far more comfortable conditions.