Algeria comprises 2,381,741 square kilometers of land, more than four-fifths of which is desert, in northern Africa, between Morocco and Tunisia. It is the second largest country in Africa, after Sudan. Its Arabic name, Al Jazair (the islands), derives from the name of the capital Algiers (Al Jazair in Arabic), after the small islands formerly found in its harbor. It has a long Mediterranean coastline. The northern portion, an area of mountains, valleys, and plateaus between the Mediterranean Sea and the Sahara Desert, forms an integral part of the section of North Africa known as the Maghreb. This area includes Morocco, Tunisia, and the northwestern portion of Libya known historically as Tripolitania.
Algeria lies mostly between latitudes 19° and 37°N (a small area is north of 37°), and longitudes 9°W and 12°E. Most of the coastal area is hilly, sometimes even mountainous, and there are a few natural harbours. The area from the coast to the Tell Atlas is fertile. South of the Tell Atlas is a steppe landscape, which ends with the Saharan Atlas; further south, there is the Sahara desert.
The Ahaggar Mountains, also known as the Hoggar, are a highland region in central Sahara, southern Algeria. They are located about 1,500 km (932 mi) south of the capital, Algiers and just west of Tamanghasset. Algiers, Oran, Constantine, Tizi Ouzou and Annaba are Algeria's main cities. Currently the second largest country in Africa after Sudan, Algeria will become the continent's largest country when Southern Sudan secedes from Sudan in July 2011.
Climate
Northern Algeria is in the temperate zone and enjoys a mild, Mediterranean climate. It lies within approximately the same latitudes as southern California and has somewhat similar climatic conditions. Its broken topography, however, provides sharp local contrasts in both prevailing temperatures and incidence of rainfall. Year-to-year variations in climatic conditions are also common.
In the Tell, temperatures in summer average between 21 and 24 °C (70 and 75 °F) and in winter drop to 10 to 12 °C (50 to 54 °F). Winters are not cold, but the humidity is high and houses are seldom adequately heated. In eastern Algeria, the average temperatures are somewhat lower, and on the steppes of the High Plateaus winter temperatures hover only a few degrees above freezing. A prominent feature of the climate in this region is the sirocco, a dusty, choking south wind blowing off the desert, sometimes at gale force. This wind also occasionally reaches into the coastal Tell.
In Algeria only a relatively small corner of the Sahara lies across the Tropic of Cancer in the torrid zone, but even in winter, midday desert temperatures can be very hot. After sunset, however, the clear, dry air permits rapid loss of heat, and the nights are cool to chilly. Enormous daily ranges in temperature are recorded.
Rainfall is fairly abundant along the coastal part of the Tell, ranging from 400 to 670 mm (15.7 to 26.4 in) annually, the amount of precipitation increasing from west to east. Precipitation is heaviest in the northern part of eastern Algeria, where it reaches as much as 1,000 mm (39.4 in) in some years. Farther inland the rainfall is less plentiful. Prevailing winds that are easterly and northeasterly in summer change to westerly and northerly in winter and carry with them a general increase in precipitation from September to December, a decrease in the late winter and spring months, and a near absence of rainfall during the summer months.
In this region, midday desert temperatures can be hot year round. After sunset, however, the clear, dry air permits rapid loss of heat, and the nights are cool to chilly. Enormous daily ranges in temperature are recorded. The highest official temperature was 50.6 °C (123.1 °F) at In Salah.
Farther inland, the rainfall is less plentiful. Prevailing winds that are easterly and north-easterly in summer change to westerly and northerly in winter and carry with them a general increase in precipitation from September through December, a decrease in the late winter and spring months, and a near absence of rainfall during the summer months. Algeria also has ergs, or sand dunes between mountains. Among these, in the summer time when winds are heavy and gusty, temperatures can get up to 110 °F (43.3 °C).