Sierra Leone - Climate
Temperatures and humidity are high, and rainfall is heavy. The mean temperature is about 27° C (81° F ) on the coast and almost as high on the eastern plateau. There are two distinct seasons: the dry season, from November to April, and the wet season, over the rest of the year, with the heaviest precipitation in July, August, and September. Rainfall is greatest along the coast, especially in the mountains, where there is more than 580 cm (230 in) annually, but it averages more than 315 cm (125 in) a year in most of the country, with 366 cm (144 in) at Freetown. The relative humidity ranges from an average of 80% during the wet season to about 50% during the dry season.