Some of the descending air in the subtropical belt forms surface winds which return towards the equator. The rest travels towards the higher latitudes, delivering warm air masses to the temperate regions of the world at 50 to 60 latitude. Here they collide with cold polar air, and the warm air is forced to rise, developing a zone of low pressure. This temperate low-pressure zone is cyclonic in nature, and is associated with the development of frontal depressions. Such weather features are common to the UK and bring with them bouts of rain and intermittent sunshine.
Depressions are more dominant in winter than in summer.
During the warmer half of the year, subtropical high-pressure systems sometimes expand poleward to have a calming influence on the weather in the temperate latitudes. The very low temperatures over the polar regions make the air there heavy, forcing it to descend, creating a zone of high pressure. The permanent and thick snow and ice cover in the Antarctic and Arctic regions give false impression that they receive a lot of snowfall. In fact, the polar regions can be as dry as the hot deserts of the subtropical climate zone , and it can take many years for even small amounts of snowfall to accumulate. The positions of the world's continents and major oceans significantly influences the major pressure belts that develop from the general circulation of the atmosphere.