Why do Jamaica’s mountains receive more rain than its southern savannas?

Jamaica’s mountains receive significantly more rainfall than its southern savannas due to the phenomenon of orographic precipitation.21

The island’s climate is dominated by moisture-laden trade winds blowing from the northeast. As these winds encounter the island's interior mountains, they are forced upward. This rising air cools, causing the moisture to condense and fall as heavy rain on the windward slopes—such as those in the parish of Portland and the Blue Mountains—where annual rainfall can exceed 130 to 200 inches.231

Conversely, the southern and southwestern regions of the island lie on the leeward side of these mountain ranges. By the time the air reaches these areas, it has already lost much of its moisture, creating a rain shadow effect. Consequently, the southern savannas experience significantly less precipitation, resulting in hot, dry conditions.21