This classification is more or less a synthesis of all the climatic classifications designed so far. The types are:
i. Hot climates
ii. Temperate climates
iii. Cold climates
iv. Desert climates
Grouped under the hot climates are the equatorial and tropical hot climates. This group is a zone which goes beyond the tropics. Much consists of ocean, but large parts of Africa, South America, Australia, and the peninsulas and islands of southern Asia are included.
The mean annual temperature in the hot climates exceeds 21°C.The equatorial area experiences double maxima of rain. The marine area of the tropics has no marked dry season while it is marked in the continental area.
The temperate climates consist of the warm and cool temperate climates. The warm temperate group transits between the tropical area and the cool temperate latitudes.
The summers here are hot and with no cold season (that is no month has a temperature below 6°C). The western margin (Mediterranean) of the warm temperate climates experiences winter rain while the eastern margin has uniform rain. In the case of cool temperate climates, a cold season of between one and five months exists with temperature below 6°C. This group lies between latitudes 40° and 55° north and south of the equator. Around the marine area, there is uniform rain while within the continent; there is summer maximum of rain.
The cold climates here are made up of the tundra and polar climates. They are found within the westerly wind-belt, and possess a long cold season covering six or more months with temperature below 6°C. The marine area experiences uniform rain while the continental area has summer maximum of rain.
Included in the desert climates are the hot and cold desert climates. Hot desert climates are found, for example in North Africa and Asia, beginning from Morocco to Pakistan, and in Australia occupying most of the centre. Cold desert climates are the most popular poleward about latitudes 55° and 60° north and south of the equator. While the temperature of the hot desert climates never goes below 6°C, that of the cold desert climates goes far below 6°C. For both climates, there is usually little or no rain. In fact, deserts exist as a result of aridity.