The uniqueness of Australian weather

In terms of the weather, Australia's long southern coastline is unique in the world. It stretches more than 3000km roughly along the 35th parallel of latitude.

To the south, the Southern Ocean extends 3000km to the Antarctic continent. From there, outbreaks of very cold polar air move northwards, warming somewhat as they pass over the ocean. The air is still cool when it reaches Australia.

Inland from the southern coast, a large proportion of the country is arid or semi-arid, with low rainfall and very hot summers.

Air coming from the hot interior to the coast meets the cold air from Antarctica, giving southern Australia highly variable weather.

The other southern hemisphere continents do not have long coastlines parallel to Antarctica. The southern African coastline is more rounded, and is further north. While the tip of South America comes to within 1000km of the Palmer Peninsula on Antarctica, the long spine of the Andes means that there is no contrasting hot interior.

In the northern hemisphere, the coastlines of the great land masses that surround the Arctic Ocean lie well within the Arctic Circle. In winter there is no difference between the ice-covered water and the snow-covered land; while the short summers at these latitudes mean there is no marked contrast between sea and land.

(bottom right) Part of Australia's long southern coastline.