Tunisia is a country situated on the Mediterranean coast of North Africa, halfway between the Atlantic Ocean and the Nile Valley. It is enclosed by Algeria in the west and Libya in the south-east. An immediate southern turn of its seashore gives Tunisia two faces on the Mediterranean.

Despite its relatively small size, Tunisia has huge geographical and climatic variety. The Dorsal, an extension of the Atlas Mountains, traverses Tunisia in a northeasterly direction from the Algerian border in the west to the Cape Bon peninsula. North of the Dorsal is the Tell, a region characterized by low, rolling hills and plains, although in the northwestern corner of Tunisia, the land reaches elevations of 1,050 meters.
The Sahil is a plain along Tunisia's eastern Mediterranean coast well-known because of its olive monoculture. Inland from the Sahil, between the Dorsal and a variety of hills south of Gafsa, are the Steppes. Much of the southern region is semi-arid and desert.
Tunisia has a seashore 1,148 kilometres in length. In maritime terms, the country claims a adjacent zone of 24 nautical miles (44.4 km; 27.6 mi), and a territorial sea of 12 nmi (22.2 km; 13.8 mi).
Tunisia's weather is temperate in the north, with mild rainy winters and hot, dry summers.     The south of the state is desert. The terrain in the north is mountainous, which, moving south, gives way to a hot, dry central plain. The south is semiarid, and merges into the Sahara. A series of salt lakes, known as chotts or shatts, lie in an east-west line at the northern edge of the Sahara, extending from the Gulf of Gabes into Algeria. The lowest point is Shatt al Gharsah, at -17 m, and the highest is Jebel ech Chambi, at 1544 metres.

 

Four major physical regions make up Tunisia: the Atlas Mountains in the north; the central plateau; the Sahel, or eastern coastal plain; and the Sahara in the south.

The Atlas Mountains of Tunisia, part of the great North African chain, consist of the wooded Tell Atlas and the Saharan Atlas ranges. Generally low in elevation, they descend gradually to the northeast and end at Cape Blanc and Cape Bon. Tunisia's highest point, nearly 5,100 feet (1,550 m), is in the Saharan Atlas near the Algerian border. Between the two ranges lies the fertile valley of the Medjerda, Tunisia's only river with a year-round flow.

The central plateau lies south of the Atlas ranges at an elevation of 1,000 to 2,500 feet (300 to 760 m). There are a few hills and low mountains, but much of the region is a flat steppe sloping gently toward the east coast. The few rivers that cross the plateau flow only after occasional heavy rains.

The Sahel begins near Bizerte in the far north and extends southward to the vicinity of Sfax. It is a flat, low plain with a few salt flats, and is interrupted only by the northeastern tip of the Saharan Atlas.

The Sahara, beginning at about the latitude of the Gulf of Gabès, is a large, arid region occupying roughly half of Tunisia. West of Gabès is a broad depression lying as much as 70 feet (20 m) below sea level and containing several intermittent salt lakes, or chotts. Farther south is the Great Eastern Erg, a vast region of dunes and drifting sand. Separating this region from the coast are the barren Ksour Mountains, which stretch southward from Gabès into Libya.

 

Northern Tunisia has a typically Mediterranean climate with hot, dry summers and mild, moderately rainy winters. Temperatures in the coastal areas average near 80° F. (27° C.) during summer and 55° F. (13° C.) in winter. Precipitation totals roughly 15 to 30 inches (380 to 760 mm) annually, depending on location. Lower temperatures and larger amounts of precipitation, including snow, occur in the Atlas Mountains. South of the mountains the climate becomes progressively hotter and drier, reaching an extreme in the Sahara. Little or no rain occurs in the Sahara, and temperatures there often exceed 110° F. (43° C.) during summer.

A very hot, dry wind from the Sahara, locally called a chili, occasionally blows northward across the country, especially during spring.