Visiting Argentina in September: Weather, Events & Travel Tips

September is the month Argentina shakes off winter. Buenos Aires brightens, temperatures rise quickly through the month, and the southern hemisphere spring arrival transforms the country’s mood and practical options.

Buenos Aires in September

Buenos Aires in September is noticeably better than August. Temperatures climb from around 15°C in early September to 20°C or higher by month’s end. Rain is possible but sunshine becomes more common, and the jacaranda trees that line many city streets begin to bloom toward late October — September sees the first hints.

The city operates at full cultural pace through September. The Buenos Aires Design week and various art fairs take place in spring — check the current year’s calendar as dates shift. The outdoor food and artisan markets in Palermo and San Telmo reopen with fuller schedules after the winter lull.

Spring in Buenos Aires also means the city gradually fills with international visitors building toward the November peak — September is ahead of this curve, still relatively uncrowded.

Patagonia in September: Season Opening

September is the transitional month in Patagonia. El Calafate is open year-round and the Perito Moreno Glacier walk operates in September. El Chaltén, the trekking capital, typically opens for the season around late October — some accommodation opens in late September, but full trail access and services are not yet available.

Peninsula Valdés on the Atlantic coast: September and October are the peak months for southern right whale watching at Peninsula Valdés, near Puerto Madryn. The season runs roughly June to December, but the highest concentration of whales — including mother and calf pairs close to shore — occurs in September and October. Boat tours depart from Puerto Pirámides, about 100km from Puerto Madryn. Orcas hunting sea lion pups along the beach at Punta Norte are also occasionally observed in this period. This is one of Argentina’s premier wildlife experiences and pairs well with a Buenos Aires trip.

Northwest Argentina in September

The northwest is excellent in September — dry, clear, and warming up after winter. Salta and Jujuy are comfortable, and the high-altitude routes are reliable. The Quebrada de Humahuaca and Salinas Grandes are accessible without weather complications. This is a strong month for the northwest before it begins warming significantly in October and November.

Mendoza in September

September is the start of the growing season in Mendoza’s vineyards — the vines are beginning to bud after winter dormancy. Winery visits are pleasant and uncrowded. The Andes snow coverage is at its maximum, making the mountain views from the valley exceptional. Temperatures are around 18–23°C.

Iguazú Falls in September

September is a reliable month for Iguazú. The falls are operating at a medium water level (less than wet season, more than dry). Temperatures are 24–28°C — warmer than winter but not the extreme heat of January. One of the more balanced months to visit.

Practical Notes for September

• Patagonia bookings: If trekking in October is the plan, September is the time to confirm El Chaltén accommodation bookings. Popular lodges for October fill in September.
• Whale watching: Book Peninsula Valdés whale watching tours in advance for September — this is within the peak whale season and tours fill up at weekends.
• Buenos Aires spring: The city’s outdoor energy picks up through September. The Feria de Mataderos (a traditional gaucho market and festival) typically runs on Sundays from around September through December.
• Temperatures vary: Buenos Aires in early September can still feel wintry. Pack layers that cover both cool and mild conditions.
• Ski season end: The ski resorts at Bariloche and Las Leñas wind down in September. The season typically ends around late September, though timing varies by snowfall year.