Monte Desert Monte Desert The Monte Desert is a South American ecoregion, lying entirely within Argentina and covering approximately the submontane areas of Catamarca, La Rioja, San Juan, San Luis and Mendoza Provinces, plus the western half of La Pampa Province and the extreme north of Río Negro Province. The desert lies southeast of the Atacama Desert in Chile, north of the larger Patagonian Desert, east of the Andes and west of the Sierra de Córdoba. The delineations between the Monte Desert, the Atacama Desert, and the Patagonian Desert are not exact and the desert seems to be more-or-less continuous with the
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