Australia Geography, Climate & Nature

Australia is the world's smallest continent and sixth-largest country, dominated by a vast, arid interior known as the Outback that covers most of the continent's landmass. Most of the population lives in a narrow band along the eastern and southeastern coast, from Cairns down through Sydney, Melbourne, and Adelaide.

The Great Dividing Range, Australia's longest mountain chain, runs the length of the east coast, separating the fertile coastal strip from the dry interior and its red-earth deserts, home to landmarks like Uluru.

Offshore, the Great Barrier Reef stretches over 2,300 kilometers along the Queensland coast, the largest coral reef system on Earth, while the island state of Tasmania adds a cooler, more rugged landscape distinct from the rest of the country.

Australia's size means it spans multiple climate zones at once, and being in the Southern Hemisphere, its seasons run opposite to Europe and North America -- summer falls in December-February, winter in June-August.

The tropical north, including Darwin and Cairns, has a wet/dry climate rather than four seasons -- hot and humid year-round, with a monsoonal wet season (November-April) and a dry season (May-October) that's far more comfortable for travel.

The southeast has a temperate climate with genuine seasonal variation, while the interior Outback is arid and extreme, with summer temperatures that can exceed 45°C (113°F). Tasmania, farthest south, is the coolest part of the country.

Australia separated from the other continents early and stayed separate, and its biology is the result: 46 per cent of its birds, 69 per cent of its mammals, 94 per cent of its amphibians and 93 per cent of its reptiles are found nowhere else on earth. Those are among the highest endemism figures of any country, and they are why Australian wildlife does not merely differ from what a visitor knows -- it occupies the same roles with entirely different animals.

The marsupials are the clearest case. Because placental mammals largely did not reach the continent, marsupials -- the macropods, possums and dasyuromorphs -- fill many of the ecological niches that placental animals occupy elsewhere in the world. Australia is also home to two of the five known living monotreme species, the egg-laying mammals, which exist nowhere else.

Habitat runs from tropical rainforest in the north-east through savanna and desert across the interior to temperate forest and alpine country in the south-east and Tasmania, with the reef systems offshore. The pressures are fire, clearing and introduced species, and the southern and eastern fringes -- where the people are -- carry most of the damage.

The animals are the reason many people come, and Australia obliges in both directions: the endemic mammals are genuinely easy to see, and the country has more venomous than non-venomous species of snake. Kangaroos and wallabies are common enough to be a driving hazard at dusk, koalas are localised but reliable where they occur, and wombats, echidnas and possums turn up in ordinary bushland near cities.

The monotremes are the ones worth planning for. The platypus is the animal most visitors want and most visitors miss: it is shy, crepuscular and concentrated in eastern freshwater streams, so it rewards a dawn or dusk sit at a known pool rather than a walk. Echidnas are easier and turn up almost anywhere.

The venomous list is long -- snakes, spiders, scorpions, octopus, jellyfish, molluscs, stonefish and stingrays -- and the honest framing is that it changes behaviour rather than plans. Watch where you put your hands and feet in the bush, swim between the flags, and take the marine stinger season in the tropical north seriously, because that is the one with a fixed season and a clear local rule.