In climatology, the term megathermal (or less commonly, macrothermal) is sometimes used as a synonym for "tropical." Climatology is the science that studies climates and investigates their phenomena and causes. ... The tropics are the geographic region of the Earth centered on the equator and limited in latitude by the two tropics: the Tropic of Cancer in the north and the Tropic of Capricorn in the southern hemisphere. ...

The word megathermal is derived from two Greek words meaning "having great heat."

In order for a particular place to qualify as having a megathermal climate, every single month out of the year must have an average temperature of 18°C or above. Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ...

Megathermal climates are sometimes split into two temperature-based subsets — equatorial and tropical (the latter used here in the sense of "outer tropical") — with "equatorial" denoting little or no variation in temperature throughout the year and "tropical" denoting significant seasonal variation, even though no month has an average temperature of below 18°C. In addition, what temperature fluctuations do exist in an equatorial climate will typically bear no relationship to the astronomical seasons for the applicable side of the equator, while in the (outer) tropical subtype the temperature will move in concert with the seasons, the time of higher sun and longer days being warmest and the time of lower sun and shorter days coolest. The equator is an imaginary line drawn around a planet, halfway between the poles. ...

These climates can also be subdivided on the basis of rainfall, as examples of humid, semiarid and arid places can all be found within the megathermal category (although the region of arid megathermal climate is small compared with the extent of deserts existing in other climate zones, particularly the neighboring subtropical zone). Rain falling For other uses see Rain (disambiguation). ... Humidity is the quantity of moisture in the air. ... The steppe of Western Kazakhstan in early spring In physical geography, steppe (from Slavic step) is a plain without trees (apart from those near rivers and lakes); it is similar to a prairie, although a prairie is generally reckoned as being dominated by tall grasses, while short grasses are said... A dune in the Egyptian desert In geography, a desert is a landscape form or region that receives little precipitation. ... Subtropical climate is the form of climate found immediately poleward of the zone of tropical climate. ...

See also

Mesothermal
Microthermal In climatology, the term microthermal is used to denote the continental climates of Eurasia and North America. ...