World map with the intertropical zone highlighted in crimson
Areas of the world with tropical climates.

The tropics are a region of the Earth surrounding the Equator. They are delimited in latitude by The Tropic of Cancer in the Northern Hemisphere at 23°26′12.6″ (or 23.43683°) N and the Tropic of Capricorn inthe Southern Hemisphere at 23°26′12.6″ (or 23.43683°) 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 the zenith, 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[1] and contain 36% of the Earth's landmass.[2] As of 2014, the region is home to 40% of the world population, and this figure is projected to reach 50% by the late 2030s.[3]

Seasons and climate

A graph showing the zonally averaged monthly precipitation. The tropics receive more precipitation than higher latitudes. The precipitation maximum, which follows the solar equator through the year, is under the rising branch of the Hadley circulation; the sub-tropical minima are under the descending branch and cause the desert areas.
Aerial view of Bora Bora, French Polynesia
Tropical sunset over the sea in Kota Kinabalu, Malaysia

"Tropical" is sometimes used in a general sense for a tropical climate to mean warm to hot and moist year-round, often with the sense of lush vegetation.

Many tropical areas have a dry and wet season. The wet season, rainy season or green season is the time of year, ranging from one or more months, when most of the average annual rainfall in a region falls.[4] Areas with wet seasons are disseminated across portions of the tropics and subtropics.[5] 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.[6] Tropical rainforests technically do not have dry or wet seasons, since their rainfall is equally distributed through the year.[7] Some areas with pronounced rainy seasons see a break in rainfall during mid-season when the intertropical convergence zone or monsoon trough moves poleward of their location during the middle of the warm season;[8] typical vegetation in these areas ranges from moist seasonal tropical forests to savannahs.

When the wet season occurs during the warm season, or summer, precipitation falls mainly during the late afternoon and early evening hours. The wet season is a time when air quality improves, freshwater quality improves and vegetation grows significantly, leading to crop yields late in the season. Floods cause rivers to overflow their banks, and some animals to retreat to higher ground. Soil nutrients diminish and erosion increases. The incidence of malaria increases in areas where the rainy season coincides with high temperatures. Animals have adaptation and survival strategies for the wetter regime. The previous dry season leads to food shortages into the wet season, as the crops have yet to mature.

However, regions within the tropics may well not have a tropical climate. Under the Köppen climate classification, much of the area within the geographical tropics is classed not as "tropical" but as "dry" (arid or semi-arid), including the Sahara Desert, the Atacama Desert and Australian Outback. Also, there are alpine tundra and snow-capped peaks, including Mauna Kea, Mount Kilimanjaro, and the Andes as far south as the northernmost parts of Chile and Argentina.

Other Languages
Afrikaans: Trope
Ænglisc: Wearm geard
Bân-lâm-gú: Jia̍t-tài
беларуская: Тропікі
беларуская (тарашкевіца)‎: Тропікі
भोजपुरी: उष्णकटिबंध
български: Тропици
bosanski: Tropi
brezhoneg: Trovan
català: Zona tropical
Cymraeg: Trofannau
dansk: Tropisk
Deutsch: Tropen
Diné bizaad: Deesdoigi
dolnoserbski: Tropy
eesti: Troopika
Ελληνικά: Τροπική ζώνη
Esperanto: Tropikoj
euskara: Tropiko
français: Tropique
Frysk: Tropen
Gaeilge: An Teochrios
galego: Trópico
한국어: 열대
hornjoserbsce: Tropy
hrvatski: Tropi
Ido: Tropiko
Ilokano: Tropiko
Bahasa Indonesia: Tropika
íslenska: Hitabelti
italiano: Zona torrida
Basa Jawa: Tropika
ქართული: ტროპიკები
қазақша: Тропиктер
Kiswahili: Tropiki
Kreyòl ayisyen: Twopik
Кыргызча: Тропик
Latina: Zona tropica
latviešu: Tropu josla
lietuvių: Atogrąžos
magyar: Trópusok
македонски: Тропски појас
മലയാളം: ഉഷ്ണമേഖല
Bahasa Melayu: Tropika
မြန်မာဘာသာ: အပူပိုင်းဇုန်
Nederlands: Tropen (geografie)
日本語: 熱帯
Nordfriisk: Troopen
norsk: Tropene
norsk nynorsk: Tropane
occitan: Tropic
oʻzbekcha/ўзбекча: Tropik mintaqalar
Plattdüütsch: Tropen
português: Trópico
русский: Тропики
саха тыла: Тропик
Scots: Tropics
Simple English: Tropics
slovenčina: Tropické pásmo
slovenščina: Tropi
српски / srpski: Тропи
srpskohrvatski / српскохрватски: Tropi
Basa Sunda: Tropis
Tagalog: Tropiko
Türkçe: Dönence
українська: Тропіки
اردو: منقلبین
Tiếng Việt: Nhiệt đới
walon: Tropike
Winaray: Tropiko
Wolof: Gëwéel
吴语: 热带
粵語: 熱帶地區
中文: 热带