The northwestern portion of Rajasthan is generally sandy and dry. Most of this region is covered by the Thar Desert which extends into adjoining portions of Pakistan. The Aravalli Range does not intercept the moisture-giving southwest monsoon winds off the Arabian Sea, as it lies in a direction parallel to that of the coming monsoon winds, leaving the northwestern region in a rain shadow. The Thar Desert is thinly populated. This region receives less than 400 mm of rain in an average year. Temperatures can exceed 45 °C in the summer months and drop below freezing in the winter. The Luni River and its tributaries are the major river system of desert region, draining the western slopes of the Aravallis and emptying southwest into the great Rann of Kutch wetland in neighboring Gujarat. The Ghaggar River, which originates in Haryana, is an intermittent stream that disappears into the sands of the Thar Desert in the northern corner of the state and is seen as a remnant of the primitive Saraswati River.
The Aravalli Range and the lands to the east and southeast of the range are generally more fertile and better watered. Eastern and southeastern Rajasthan is drained by the Banas and Chambal rivers, tributaries of the Ganges.
Rajasthan's economy is primarily agricultural and pastoral. Wheat, Pearl-millet and Barley are cultivated over large areas, as are pulses, sugarcane, and oil seeds. Cotton and tobacco are the state's cash crops. Rajasthan is among the largest producers of edible oils in India and the second largest producer of oil seeds. Rajasthan is also the biggest wool-producing state in India and the main opium producer and consumer. There are mainly two crop seasons. The water for irrigation comes from wells and tanks. The Indira Gandhi Canal irrigates northwestern Rajasthan.
The main industries are mineral based, agriculture based and textiles. Rajasthan is the second largest producer of polyester fiber in India. Rajasthan is pre-eminent in quarrying and mining in India. The Taj Mahal was built from the white marble which was mined from a town called ‘Makrana’. Rajasthan is presently earning rupees 15 Crore per day as revenue from crude oil sector which is presently 1.75 Lakh barrel per day.
Rajasthan is famous for its forts, intricately carved temples, and decorated ‘havelis’, which were built by ‘Rajput’ kings. Rajasthan attracts about 14 percent of total foreign visitors which is the fourth highest among Indian states. It is fourth also in Domestic tourist visitors. Endowed with natural beauty and a great history, tourism is a flourishing industry in Rajasthan. The palaces of Jaipur, Ajmer-Pushkar, the lakes of Udaipur, the desert forts of Jodhpur and Jaisalmer rank among the most preferred destinations in India for many tourists both Indian and foreign. Tourism accounts for eight percent of the state's domestic product.