Climate of Australia

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, so that the rainfall pattern over Australia is highly seasonal. Australia's rainfall is the lowest of all continents except Antarctica. 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 part desert.

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 Northern Hemisphere continents during winter. Consequently, its winter is relatively mild, so that there isn't the great contrast between summer and winter temperatures there is 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 zero. Nonetheless, minimum temperatures are moderated.

The El Niño-Southern Oscillation is associated with seasonal abnormality in many areas in the world. Australia is one of the continents most affected and experiences extensive droughts alongside considerable wet periods. Occasionally a dust storm will blanket a region and there are reports of the occasional tornado. Tropical cyclones, heat waves, bushfires and frosts in the country are also associated with the Southern Oscillation. Rising levels of salinity and desertification in some areas is ravaging the landscape.

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