In order to classify Climatic Zones, climate can be considered at a variety of spatial and time scales.
|Horizontal Scale (km)||Vertical Scale (km)||Time Scale|
|Global||2 * 103||3 - 10||1 - 6 months|
|Regional||5 * 102 to 103||1 - 10||1 - 6 months|
|Local||1 to 10||102 to 10-1||1 - 24 hours|
At the geographic world map level, the Zonal classification is based on maximum and minimum temperatures and the temperature range as well as the total and seasonal distribution of precipitation. A simple summary of climatic zones is as follows:
|Polar||very cold and dry all year|
|Temperate||cold winters and mild summers|
|Arid||dry, hot all year|
|Tropical||hot and wet all year|
|Mediterranean||mild winters, dry hot summers|
|Mountains (Tundra)||very cold all year|
Many attempts have been made to classify the many disparate climates on Earth into a comprehensive and comprehensible system. One of the earliest began with Aristotle and his discussion of Temperate, Torrid, and Frigid Zones. The system that seems to be in almost universal use now is the Köppen system, developed by German climatologist and amateur botanist Wladimir Koppen in 1928.
The modified Koppen system uses letters to denote the six major climate regions and their 24 sub-classifications. These regions are based on average monthly temperature and precipitation values. Whilst it does not take full account of factors such as cloudiness, solar radiation, wind or even extremes in temperature, it still remains a useful system.
In Europe, the Climates along the Mediterranean and towards the East are much warmer and brighter than those towards the North and West.
The Indian subcontinent also shows considerable diversity from the West to East from the North to South ranging from desert to equatorial. (See Climate Zones Map India). Even a small island of Srilanka has three distinct climatic zones.
Within the same climatic zone, some locations may have contrasting or variable climatic conditions. These may be caused by the following factors:
Temperature range increases with distance from the equator. Also, temperatures decrease as you move away from the equator. This is because the suns rays are dispersed over a larger area of land as you move away from the equator. This is due to the curved surface of the earth. In addition Polar Regions are colder because the suns rays have further to travel compared to place on the equator. Altitude Temperatures decrease with height. The air is less dense and cannot hold heat as easily.
If winds are warm - they have been blown from a hot area - they will raise temperatures. If winds have been blown from cold areas they will lower temperatures.
Land heats and cools faster than the sea. Therefore coastal areas have a lower temperature range than those areas inland. On the coast winters are mild and summers are cool. In inland areas temperatures are high in the summer and cold in the winter.
Slopes facing the sun are warmer than those that are not. Thus south facing slopes in the northern hemisphere are usually warm whereas slopes facing north in the southern hemisphere are warmest.