<P> Australia's climate is governed largely by its size and by the hot, sinking air of the subtropical high pressure belt . This moves north and south with the seasons . But it is variable, with frequent droughts lasting several seasons--thought to be caused in part by the El Niño - Southern Oscillation . The climate varies widely due to its large geographical size, but by far the largest part of Australia is desert or semi-arid . Only the south - east and south - west corners have a temperate climate and moderately fertile soil . The northern part of the country has a tropical climate, varied between tropical rainforests, grasslands and desert . </P> <P> Because Australia is a small continent, separated from polar regions by the Southern Ocean, it is not subject to the movements of frigid polar air that sweep over the continents in the northern hemisphere during winter . Consequently, its winter is relatively mild, so that there aren't any great contrast between summer and winter temperatures that is present in the northern continents . Yet in many parts of the country, seasonal highs and lows can be considerable: temperatures have ranged from above 50 ° C (122 ° F) to well below 0 ° C (32 ° F). Nonetheless, minimum temperatures are moderated . </P>

Most of australia has one of the what climates