When to visit Cuyo

Cuyo is dry, high and continental, which makes its seasons sharper than most of Argentina’s. Summer days on the desert floor pass 38 °C; winter nights in the cordillera go well below zero. Between those extremes sit two very good windows, and they are not the same window for every province.

Harvest: March and April

If you are here for wine, come for the vendimia. The grapes come in through March and into April, the wineries are working rather than performing, and the whole of Mendoza turns out for the Fiesta Nacional de la Vendimia in the first week of March. Book accommodation months ahead — this is the one time of year the city genuinely fills up.

The weather helps. Days sit in the mid-twenties, the nights cool off, and the cordillera is still clear of winter snow.

The high Andes: November to March

Anything above about 2,500 metres has a short season. The Aconcagua trekking and climbing permits run roughly from mid-November to mid-March, and the Ruta 7 pass to Chile, while open year-round in principle, closes without warning in winter storms. If your trip depends on crossing to Chile or on walking in the Horcones valley, that is your window.

The desert: avoid midsummer

San Juan’s badlands are a different problem. Ischigualasto in January means walking a shadeless clay floor at 40 °C, and the park sensibly starts its tours earlier in the day for it. April to June and September to November are far better: cool mornings, hard light, almost nobody there.

San Juan’s other draw — its night skies — argues for the new moon in any month. The Leoncito observatories sit under some of the clearest air in the hemisphere, and a full moon washes it all out.

San Luis: the mild exception

The sierras of San Luis are 1,000 metres lower and considerably wetter than the rest of Cuyo, and they stay pleasant when Mendoza bakes. September to December and March to May are the best stretches. January and February fill with Argentine holidaymakers in Merlo and along the Conlara valley; the walking is still good, the prices are not.

The short answer

• Wine first: March and April.
• Mountains first: December to February.
• Desert and stars first: April to June, or September to November.
• Avoid: late June to August above 2,000 m, and January on the desert floor.