Basically, Rajasthan is marked with the tropical climate.
Months from October to February are very cold and March to September are
very hot. The state gets very scant rainfall and in the desert region,
during summer, people fetch water from miles away. The southern part of
the state is watered by River Luni and the Chambal River and its
tributaries form an alluvial basin in Kota.
Rajasthan is one of the driest regions of India. Its location on the margins of pure desert has made much of it particularly susceptible to climatic change, and fossil sand dunes as Far East as Delhi testify to the advance and retreat of the desert over the last 5,000 years. The climate varies throughout Rajasthan. Temperature
Pre-monsoon season, which extends from April to June, is the hottest season, with temperatures ranging from 32 degree Celsius to 45 degree Celsius. There is little relief from the scorching onslaught of the heat, particularly in the arid zone to the west and northwest of the Aravalli range, where temperatures often climb above 45 degree Celsius, particularly in May and June.
Summer : Max: 46°C Min: 25°C Winter : Max: 28°C Min: 8°C
Mt Abu registers the lowest temperatures at this time. In the desert region, the temperature rises as night falls. Prevailing winds are from the west end and carry dust storms.
The season of much interest to visitors is the winter, or cold season, which extends from December to March. January is the coolest month of the year. In winter, the daily maximum in most low-lying areas is 22°C to 28°C and the minimum 8°C to 14°C.
Over three-quarters of the rainfall occurs between July and September. The Aravalli range tends to experience a higher rainfall and lower temperatures throughout the year. To the southwest there is higher rainfall and marked humidity. Average rainfall varies; the western deserts accumulate about 100 mm (about 4 in) annually, while the southeastern part of the state receives 650 mm (26 in) annually, most of which falls from July through September during the monsoon season.