Located in the Southern hemisphere, Argentina’s seasons are reversed from the northern hemisphere: The summer solstice falls on December 21, the autumn equinox on March 21, the winter solstice on June 21, and the spring equinox on September 21. For most Argentines, the summer months are January and February, when schools are out of session and families take their holidays.
Because Argentina stretches from the desert tropics, where the amount of sunshine and daylight hours vary little over the year, to far southern latitudes where blustery maritime conditions are the rule and seasonal variations can be dramatic, it’s difficult to generalize about climate. Moreover, altitude plays a major role everywhere.
Thanks to their midlatitude setting and proximity to the ocean, Buenos Aires  and the surrounding pampas have a humid temperate climate, with annual precipitation of about 1,200 millimeters distributed evenly throughout the year. Summer can be hot, wet, and sticky, as temperatures frequently exceed 30°C and thunderstorms are common. Pamperos (southwesterly cold fronts) and sudestadas (cool high winds from the southeast) are the most problematic climatic phenomena; winter temperatures are mild, frosts rare, and snow almost unheard of.
Between the Río Paraná and the Río Uruguay, the Mesopotamian provinces of Entre Ríos , Corrientes , and Misiones  can be hot, humid, and flood-prone, but nighttime winter temperatures occasionally approach freezing even in the subtropical areas near the Brazilian and Paraguayan borders. West of the Paraná, the arid Chaco encompasses parts of northern Santa Fe  and Córdoba Provinces, plus Santiago del Estero, Chaco, and Formosa ; rainfall diminishes toward the west in this summertime furnace, whose dry winter is the best time to visit. Santiago del Estero gets less than half of Corrientes’s 1,200-millimeter annual rainfall.
In the desert canyons and high puna of the northernmost Andes, warm or even hot daytime temperatures often fall to or near freezing at night. Summer thunderstorms can bring heavy rains and even floods or, at higher elevations, snow; nearly rain-free, the winter months of July and August are an ideal time to travel here. In some favored microclimates, such as Tucumán, rainfall is sufficient for unirrigated agriculture. South of Tucumán, summer can be brutally hot (especially in La Rioja  and Catamarca) and rainfall is inadequate for agriculture, but irrigation has turned the Cuyo  region (primarily Mendoza  and San Juan Provinces ) into the country’s vineyard. The dry katabatic wind known as El Zonda brings stifling heat and even physical distress.
Its receding glaciers sensitive to warming, Patagonia is a living laboratory for climate-change studies. While it’s the country’s coolest region, its inclemency is often overstated—despite its geographical position at the continent’s tip, it is not Antarctica. Eastern portions of the Patagonian provinces are even arid steppe, with low rainfall but frequent high winds, especially in summer. Climatically, Tierra del Fuego is an extension of mainland Patagonia.