relating to. situated in. or characteristic of the tropics (the region on either side of the equator).
The tropics are the region of the Earth surrounding the Equator. They are delimited in latitude by the Tropic of Cancer in the Northern Hemisphere at 23°26′12.3″ (or 23.43675°) N and the Tropic of Capricorn in the Southern Hemisphere at 23°26′12.3″ (or 23.43675°) S; these latitudes correspond to the axial tilt of the Earth. The tropics are also referred to as the tropical zone and the torrid zone (see geographical zone). The tropics include all the areas on the Earth where the Sun contacts a point directly overhead at least once during the solar year (which is a subsolar point) - thus the latitude of the tropics is roughly equal to the angle of the Earth's axial tilt.
The tropics are distinguished from the other climatic and biomatic regions of Earth, which are the middle latitudes and the polar regions on either side of the equatorial zone.
The tropics comprise 40% of the Earth's surface area and contain 36% of the Earth's landmass. As of 2014[update], the region is home to 40% of the world's population, and this figure is projected to reach 50% by the late 2030s.