Climate is subtropical with a distinct hot and rainy season from June to October, and a cooler dry season from November to May. The beginning and end of the rains are marked by high temperatures and high humidity, whereas the dry season is noted for the dusty and dry trade winds (harmattan) blowing in from the central Sahara. Temperatures range from a low of 48°F (9°C) in January to a high of 110°F (43°C) in October. Because of the cooling effect of the ocean, temperatures are lower along the coast than in the interior. Rainfall varies widely from year to year but ranges from an annual mean of 48 inches in the west to 34 inches upriver.
Because of the humid climate and the salt air along the coast, metal rusts rapidly in The Gambia, and houses near the sea may be affected by the corrosive salt air. Termites abound year round in soils and woodwork. During the dry season, the harmattan winds blow in a fine dust. However, the moderate temperatures during the dry season with mostly sunny days give The Gambia one of West Africa’s more pleasant climates.