Marwar is a sandy plain lying northwest of the Aravalli Range, which runs southwest-northeast through Rajasthan state. The Aravallis wring much of the moisture from the southwest monsoon, which provides most of India's rainfall. Annual rainfall is low, ranging from 10 cm to 40 cm. Temperatures range from 48 to 50 degrees Celsius in the summer, to below freezing point in winter. The northwestern thorn scrub forests lie next to the Aravalli Range, while the rest of the region lies in the Thar Desert.