Tropical Rain Belt

The rainfall, and hence the tropical climate is dominated by the tropical rain belt, which oscillates from the northern to the southern tropics over the course of the year, roughly following the solar equator; it is largely a manifestation of the ITCZ. The tropical rain belt lies in the southern hemisphere of the Indian ocean and western Pacific ocean roughly from October to March, and during this time the northern tropics experience a dry season in which precipitation is very rare, and days are typically hot and sunny throughout. From April to September, the rain belt lies in the northern hemisphere, and a wet season occurs there, while the southern tropics experience their dry season.

The rain belt reaches roughly as far north as the Tropic of Cancer and as far south as the Tropic of Capricorn in the western Pacific ocean. Its variation in the Western Hemisphere is minimal, roughly between the equator and the 15th parallel north latitude. Near these latitudes, there is one wet season and one dry season annually. On the equator, there are two wet and two dry seasons as the rain belt passes over twice a year, once moving north and once moving south. Between the tropics and the equator, locations may experience a short wet and a long wet season. Local geography may substantially modify these climate patterns, however.