Generally, people classify their favorite warm vacation spots as "tropical." However, the word tropical has a specific meaning in meteorology. Knowing the difference between an area that is officially tropical and one that is called tropical by laypeople is important, especially in the areas of science and meteorology.
The term tropical has a rather specific meaning when applied to the scientific sense of the word. An area with tropical climate is one with an average temperature of above 18 degrees Celsius (64 degrees Fahrenheit) and considerable precipitation during at least part of the year. These areas are nonarid and are generally consistent with equatorial climate conditions around the world.
One type of tropical area commonly spoken of is the tropical rainforest. Many tropical areas include rainforest, where temperatures range from 70 to 85 degrees Fahrenheit year-round and more than 400 inches of rain fall annually. Temperate rainforests exist in areas other than the tropics and are differentiated only by the dry season that occurs for the temperate rainforests. Tropical rainforests are home to tens of thousands of different species of animals, even though they only cover 6 to 7 percent of the world's surface.
The reason that such heavy rain is common to most of the tropics is the way in which precipitation works in these areas. Active vertical uplift and convection begin the process, which through immense amounts of sunlight cause the evaporation of a great deal of water, which in turn falls back to the earth as rain, often in heavy thunder storms nearly every day. Storms are therefore most common in midday when the sun is at its strongest.
Areas of Tropical Climate
Three very large areas conform to the definition of a tropical climate. These are the Amazon Basin in Brazil, the Congo Basin in West Africa and much to all of Indonesia. Other, less commonly known areas that are actually tropical include the savannas of Africa and semiarid areas throughout the world. Southeast Asia and Central America are two of the most well-known tropical areas, by comparison.