The combination of southeastern trade winds and northwestern monsoons produces a hot rainy season (November—April) with frequently destructive cyclones, and a relatively cooler dry season (May—October). Rain clouds originating over the Indian Ocean discharge much of their moisture over the island's eastern coast; the heavy precipitation supports the area's rain forest ecosystem. The central highlands are both drier and cooler while the west is drier still, and a semi-arid climate prevails in the southwest and southern interior of the island. Tropical cyclones annually cause damage to infrastructure and local economies as well as loss of life. In 2004 Cyclone Gafilo became the strongest cyclone ever recorded to hit Madagascar. The storm killed 172 people, left 214,260 homeless and caused more than US$250 million in damage
