Deserts cover about 1,371,000 km (529,000 sq mi), or 18%, of the Australian mainland, but about 35% of the Australian continent receives so little rain, it is practically desert. Collectively known as the Great Australian desert, they are primarily distributed throughout the Western Plateau and interior lowlands of the country, covering areas from South West Queensland, the Far West region of New South Wales, Sunraysia in Victoria and Spencer Gulf in South Australia to the Barkly Tableland in Northern Territory and the Kimberley region in Western Australia.
By international standards, the Great Australian desert receives relatively high rates of rainfall, around 250 mm (10 in) on average, but due to the high evapotranspiration it would be correspondingly arid. No Australian weather stations situated in an arid region record less than 100 mm (3.94 in) of average annual rainfall. The deserts in the interior and south lack any significant summer rains. The desert in western Australia is well explained by the little evaporation of the cold sea current of the West Australian Current, of polar origin, which prevents significant rainfall in the interior of the continent. About 40% of Australia is covered by dunes. Australia is the driest inhabited continent, with the least fertile soils.