Temperature is one of the important climatic factors. Terrestrial habitats show a greater temperature range than aquatic ones. In temperate countries, there is a marked seasonal temperature variation, with temperatures below 0°C in winter and above 20° C in summer. In the tropics, lower temperatures are usually recorded during the rainy season than in the dry season. Lower temperatures, however, are recorded during the dry season in regions of west Africa when the harmattan, a cool wind, blows.
In aquatic habitats, temperatures decrease with depth. For example, in tropical marine waters, the temperature at the surface is 30°C , while at a depth of 1500m it is 4°C. Temperatures of terrestrial habitats , on the other had, decrease with height, with a drop of 1°C for every 150 m rise in height above sea level.
Most living organisms are killed by high temperatures; at low temperatures for metabolic activities they grow and reproduce rapidly. Many organisms living in Temperate and arctic regions show adaptations that allow them to live at low temperatures. In the tropics, where temperatures are favourable for life, the biotic community is large and varied. The luxuriant tropical rain forests and their animal life are examples of such communities.
