Size: 2,381,741 square kilometers, more than fourfifths desert.
Topography: Sharp contrast between relatively fertile, mountainous, topographically fragmented north and vast expanse of Sahara in south; northern Algeria dominated by parallel ranges of Saharan Atlas mountain system; no navigable rivers.
Climate: Mediterranean climate in coastal lowlands and mountain valleys; mild winters and moderate rainfall. Average temperatures and precipitation lower in intermountain Hauts Plateaux. Hot and arid in desert; little seasonal change in most of country but considerable diurnal variation in temperature.