The wet season (sometimes called the rainy season) is the time of year when most of a region's average annual rainfall occurs. Generally, the season lasts at least a month. The term green season is also sometimes used as a euphemism by tourist authorities. Areas with wet seasons are dispersed across portions of the tropics and subtropics.

Under the Köppen climate classification, for tropical climates, a wet season month is defined as a month where average precipitation is 60 millimetres (2.4 in) or more.

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