The Lower San Pedro Watershed covers an area of 2,272 square miles in southern Arizona and northern Mexico. The watershed is characterized by a semi-arid climate with hot summers and mild winters. The hydrology of the watershed is dominated by the San Pedro River, which provides surface water for agriculture and urban uses in the area. The snowpack in the area is generally limited, with occasional snow events in the higher elevations. The reservoirs in the watershed are important sources of water storage and recreation for the region. Interesting climatic facts and trends include increased temperatures and decreased precipitation in recent years, which have led to concerns about water availability and sustainability in the area. The Lower San Pedro Watershed is an important natural resource that supports diverse flora and fauna, including several endangered species.