Provinces of Argentina became provinces in 1951. Misiones did so in 1953, and Formosa, Neuquén, Río Negro, Chubut and Santa Cruz, in 1955. The last national territory, Tierra del Fuego, became the Tierra del Fuego, Antártida e Islas del Atlántico Sur Province in 1990. Argentina is a federation of twenty-three provinces and one autonomous city, Buenos Aires. Provinces are divided for administration purposes into departments and municipalities, except for Buenos Aires Province, which is divided into partidos and "localidades". Buenos Aires City itself is divided into communes ("comuna") and non-official neighbourhoods ("barrios"). Provinces hold all the power that they chose not to delegate
Climatic regions of Argentina temperate and arid with large thermal amplitudes, long summers, and a long frost free period which varies by altitude. In both the Quebrada de Humahuaca and Calchaquí valleys, winters are cold with frosts that can occur between March and September. In the valleys in the south in La Rioja and Catamarca Provinces, along with the southwest parts of Santiago del Estero Province, temperatures during the summer are very high averaging in January, while winters are mild averaging . Temperatures can exceed during the summer, particularly in the central valley of Catamarca (Valle Central de Catamarca) and the valley of La