Size: Total area of 1,030,700 square kilometers includes 400 square kilometers of water.

Topography: Generally flat with vast, arid plains broken by occasional ridges and outcroppings. In center of country, series of scarps facing southwest longitudinally bisect plains sandstone plateaus, some with isolated peaks, between scarps. Northeast a vast region of dunes.

Climate: Desert climate across northern three-fourths of country with diurnal extremes in temperatures and meager and irregular rainfall. During rainy season (July to September), average rainfall in far south 400 to 600 millimeters in northern two-thirds, 0 to 100 millimeters. Desert winds throughout year cause frequent sandstorms.

Data as of June 1988