The world is divided into four climate zones and two of them have sub zones. The primary factors used to determine this classification include climate, vegetation, air pressure and temperature levels. The climate zones are arctic, temperate, tropical and sub-tropical. The areas under the arctic climate are the coldest with warmest temperatures never exceeding 10 degrees Celsius. The ground is frozen all year long here. Temperate regions are a bit warmer followed by the subtropical and eventually tropical.