The Republic of Senegal lies at the westernmost point of Africa. It covers 196 722 km2 and is bounded on the north by Mauritania, on the east by Mali, on the south by Guinea and Guinea-Bissau, and on the west by the Atlantic Ocean. The Gambia cuts across the southern half of the country from west to east as a long corridor, 40 km wide and 370 km long, isolating the Casamance region in the south from the rest of Senegal. The Senegal River forms the border with Mauritania, and also (together with its tributary, the Falémé) with Mali, while the border with Guinea runs along the western spurs of the Fouta Djallon mountain massif. Senegal has an Atlantic seaboard of 600 km.
The country in general has landscapes of low plains, nowhere higher than 200 m, covered in recent sediment, mostly reddish "dior" sand. The altitude rises somewhat in the south-east, but not above 500 m. In the upper Falémé region in the southern part of the eastern zone the Bambouk plateau marks the end of the Guinean Fouta Djallon massif. The Senegambian basin is drained by three rivers with very gentle gradients, the Senegal, Gambia and Casamance, which flow through wide, flat valleys and are tidal a considerable way upriver.
Located between latitudes 12° 18´and 16° 41´ N, the whole of Senegal falls within the tropical Sudanian zone. Only the southern part, which is wetter, has any Guinean features. The SenegalMauritania border region and the Ferlo "desert" are Sahelian in character, with low, irregular rainfall. Throughout the country there is a wet summer season (July to October) and a dry season (October to June). In the south rainfall decreases inland from the coast, while in the north it decreases moving toward the coast. Rainfall also decreases from south to north (1 800 mm in Basse Casamance to 500 mm in the lower part of the Senegal valley). The average temperature on the coast is 22° C in January and 28° C in July. The harmattan blows in the dry season in inland areas, markedly raising the temperature and drying the air.
The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.