Climatic classification is the division of the Earth’s climates into a worldwide system of contiguous regions; each one of them is characterized by a relative homogeneity of the climatic elements, say temperature, pressure, rainfall, humidity.
Most climate zones tend to appear as horizontal bands, stretching basically east-to-west. This is most evident in northernmost Northern Hemisphere, but is applicable to the rest of the areas, reflecting the impact of temperature, derived from latitude. There are exceptions, of course, as for instance, the north-south orientation of highland climate zones along the Rockies (USA) and the Andes (South America). Although global climate patterns respond to large-scale controls, differences in air pressure, winds or ocean currents are responsible for the contrasts in climate between areas at similar latitude.
The classification of climate has evolved since the first one elaborated by the Greeks up to our days. Of the major climatic classification in use nowadays, the ones made in 1918 by Wladimir Köppen and the changes introduced in 1931 and 1948 by C. W. Thornthwaite are of main reference. Köppen’s “Climate Classification System”, which is very much used with minor modifications, is an empirical classification based on the annual and monthly averages of temperature and precipitation. For many scientists, this system has to be revised. Additionally, some authors prefer to classify climate zones according to latitude: low latitude climates, mid latitude or subtropical climates and high latitude climates.