Largest desert

Nearly an eighth of the world’s land surface is arid, with a rainfall of less than 25 cm (10 in) per annum. The Sahara in North Africa is the largest hot desert in the world. At its greatest length it is 5,150 km (3,200 miles) from east to west. From north to south it is between 1,280 and 2,250 km (800 and 1,400 miles). The area covered by the desert is about 9.1 million km² (3.5 million miles2).

A “desert” is simply an area that has no or very
little rainfall. By this definition, technically the largest desert must be Antarctica (14 million km2; 5.4 million miles2), which receives around 50 mm (2 in) of precipitation per year.