In the extreme west of the province is the Puna region, mostly located in the Antofagasta de la Sierra Department. The region has a desert climate with very low precipitation; most of it is concentrated during summer. This is due to the mountains that block moist air from Pacific Ocean. Mean annual precipitation decreases from north to south and from east to west; some areas receive an annual rainfall of . Owing to its high altitude, the climate is characterized by low temperatures. The thermal amplitude is large, reaching up to due to the combination of low humidity and high solar radiation.