Cartographically speaking, the tropics include all parts of the world between 23.5° north and 23.5° south latitude. These are the limits beyond which the sun never appears directly overhead at any time of the year. However, because of terrain, winds, and ocean currents, tropical climatic types may stray outside these geographical limits, or may not quite reach them.
Under the Köppen-Tregartha system, there are three basic types of climate found in the tropics. A climates are rain forests and savannas and B climates are steppes and deserts. H is a catchall for high, rugged mountains that contain localized microclimates too varied and scattered to categorize.
By Dave Bryant, copyright 2002