The tropical zones lie between Earth’s equator and 23.5° north and south latitudes. The sun’s rays strike the tropical zones perpendicular, or at right angles, to Earth’s surface. These rays transfer the most heat energy to Earth, which makes the tropics very warm year round. Temperatures in these climate zones rarely fall below 18°C (64°F), and the tropics experience only two seasons-dry and rainy.
Some regions in tropical climate zones have wet climates. The average rainfall in these regions ranges from about 175 to 250 cm per year. Other regions in the tropics have dry periods that alternate with wet ones. Winters in the tropics are generally dry, and summers aer generally wet. Much of Central America and much of northern South America have tropical climates. Central Africa, southern Asia, and the northern edge of Australia have tropical climates, too.