The climate of the eastern and northwestern coasts is dominated by the almost constant blowing of the southeasterly trade winds, which carry heavy rains during the austral winter (May to September). The central plateau and the western coast are sheltered from these winds but receive rain from the monsoon winds, which blow during the austral summer (October to April). Neither the trade winds nor the monsoons reach the southern part of the island, which consequently receives little rain and is, in places, a semidesert. The central plateau enjoys a tropical mountain climate with well-differentiated seasons. Generally speaking, the climate throughout the island is moderated by altitude, with the coast being hotter (average temperatures 21– 27° C , or 70–80° F ) and wetter than the plateau (average temperatures 13–19° C , or 55–67° F ). Toamasina (Tamatave), on the east coast, has 284 cm (112 in) of rainfall annually, while Antananarivo, inland, has about 140 cm (55 in). Occasional cyclones have been devastating.