This region comprises of all tehsils of Bikaner, Jaisalmer and Barmer districts, Phalodi, Shergarh, Osian and Jodhpur tchsils of Jodhpur district and Dungargarh, Sujangarh, Ratangarh and Sardarshahar tehsils of Churu district. This is the most arid part of the state where the annual rainfall varies from 10 to 40 cm, quite often erratic, so much so, that the entire rainfall of the year may fall on a single day and the rest of the year may be dry. In winters, the day temperatures are higher but the night temperatures may be near freezing point. Winters are of short duration, not exceeding two months - December and January. Owing to poor rainfall, surface water resources do not exist while ground water resources are often deep and brackish.
Natural vegetation is therefore, only seasonal.
With the, first showers in late July, a few grass species grow and shrubs and dwarf trees become green. But, soon after the retreat of the monsoon in mid September, the vegetation dries up, leaving only a few perennial shrubs and a thin pad of pale grass on the landscape. Mostly rainfed crops like bajra, kharif pulses, guar etc. are own during the kharif season. Rabi crops like wheat, rape-seed and mustard are grown only in areas where irrigation water is available. The Ghaggar channel,even though 7 kms.