The Thar Desert draws its name from district Tharparkar, now in Sind Province of Pakistan. It extends over 6,00,000 Sq. Km. area in the Indian Sub-continent. Within India it covers 2,86,680 Sq. Km. area of north-west states, viz., Punjab, Haryana, Rajasthan and Gujarat. he word "Desert" connotes the barren or the unproductive land where no vegetation can be produced. In desert region, the land is unfertile, water is scarce but the rainfall varies from 120 to 350 mm per year and minimum and maximum temperature varies from -4.4ºC to 48.9ºC during winter and summer respectively. The wind velocity during summer is 40 Km/hr and intense solar radiations are 200-600 cal/cm2 /per day. The humidity is minimum in the hot weather months and maximum during the monsoon, being lowest in April and highest in August. The moisture content of the air is lowest during cold season. Rainfall in the area is scanty and precarious and sub-soil water is found at a depth of 70 to 120 mt. on an average. This water too is brackish and saline and therefore not good for human consumption or irrigation. Even for the drinking purposes, people have to depend mostly on rainy water stored in the reservoirs and during the drought, which is quite often in desert, the cattle breeders and sheep farmers migrate with their herd of cattle to distant places in search of water and pasture. Taking temperature, rainfall and humidity into consideration, the climate of the north-western region is generally hot and dry and comparatively immune from epidemics. Due to the sandy nature of the soil which rapidly gets hot during the day and cools down quickly after dusk, variation of as much as 20ºC is noted in maximum and minimum temperatures.
The hot and dust raising winds sweep more or less through out the region during the summer and they are experienced in their worst and violent from in the Thar Desert. The easterly wind during monsoon is always welcomed as it always promises to bring rain. Thunder storms are also the common features of desert. Nearly 40 to 45 days are noticed as thundry days from May to July every year.
The Thar region has a great variety of natural vegetation. The most useful tree found here is KHEJRI known as king of the desert trees (Prosopis cineraria) is used as fuel, food, feed, shelter and shade. Among other vegetation found in the desert area, the prominent ones are Acacia senegal, Acacia nilotica and Prosopis juliflora, etc. The P. juliflora can grow under varied climatic and soil conditions and topography. The main grasses found in the region are Sewan and Dhaman.