About 18% of Australia’s land mass is classified as desert, covering roughly 1.37 million square kilometers. That makes it the third-largest desert region on Earth, behind only the Sahara and the Arabian Desert. But the dry story doesn’t end there: a full 70% of Australia is either arid or semi-arid, meaning the vast majority of the continent receives very little rainfall each year.
How Much of Australia Is Desert
Australia has 10 named deserts, and together they account for about 18% of the continent’s total area. The arid zone, defined as land receiving an average of 250 mm or less of rain per year, stretches across the interior from Western Australia through South Australia, the Northern Territory, and into parts of Queensland and New South Wales. Add the semi-arid fringe (250 to 350 mm of annual rainfall), and roughly 81% of the country falls into what the Australian government broadly classifies as rangelands.
So while “desert” in the strictest sense covers about a fifth of Australia, the dry, sparsely vegetated interior that most people picture when they think of the outback is far larger.
Australia’s 10 Named Deserts
The deserts vary enormously in size. According to Geoscience Australia, here are all ten, ranked from largest to smallest:
- Great Victoria Desert (Western Australia, South Australia): 348,750 km², 4.5% of the continent
- Great Sandy Desert (Western Australia): 267,250 km², 3.5%
- Tanami Desert (Western Australia, Northern Territory): 184,500 km², 2.4%
- Simpson Desert (Northern Territory, Queensland, South Australia): 176,500 km², 2.3%
- Gibson Desert (Western Australia): 156,000 km², 2.0%
- Little Sandy Desert (Western Australia): 111,500 km², 1.5%
- Strzelecki Desert (South Australia, Queensland, New South Wales): 80,250 km², 1.0%
- Sturt Stony Desert (South Australia, Queensland, New South Wales): 29,750 km², 0.3%
- Tirari Desert (South Australia): 15,250 km², 0.2%
- Pedirka Desert (South Australia): 1,250 km², less than 0.1%
Western Australia hosts, or shares, seven of the ten. The Great Victoria Desert alone is larger than the entire United Kingdom.
How Australia Compares Globally
When grouped together, Australia’s deserts form the “Great Australian Desert,” the fifth-largest desert system on the planet at about 1.37 million km². That puts it just ahead of the Gobi Desert (1.30 million km²) in China and Mongolia, but well behind the Sahara (9.2 million km²) and the Arabian Desert (2.33 million km²). All three, including Australia’s, are classified as subtropical deserts, meaning their dryness comes from persistent high-pressure weather systems rather than extreme cold.
What the Climate Feels Like
Daytime summer temperatures in the interior regularly hit 40°C (104°F), but nights can drop sharply. Winter days are milder, typically between 16°C and 24°C (61 to 75°F), while overnight lows can fall all the way to freezing. That dramatic swing between day and night is one of the defining features of Australian desert life, and it’s far more extreme than many visitors expect.
Rainfall is not just low but unpredictable. Some desert areas go years with almost no rain, then receive a sudden downpour that briefly transforms the landscape with wildflowers and temporary lakes.
Why Australia Is So Dry
Australia sits squarely beneath a belt of subtropical high pressure that pushes moisture-laden air away from the interior. The continent also lacks a major mountain range running north to south that could force moist coastal air upward and squeeze out rain. The Great Dividing Range runs along the east coast, but it mostly keeps rainfall on the coastal side, leaving the inland in a persistent rain shadow.
Recent research shows that southern Australia is getting even drier. The jet stream, which steers rain-bearing weather systems across the continent, has shifted roughly 10 degrees further toward the South Pole over recent decades. This means cold fronts and low-pressure systems that once delivered cool-season rain to southern Australia now track south of the continent entirely. The result is more frequent and intense droughts, lower dam levels, and reduced stream flows across southern coastal regions.
Life in the Desert
Despite the harsh conditions, Australia’s deserts support a surprising range of life, much of it found nowhere else on Earth. Spinifex grass, a tough, dome-shaped plant, dominates vast stretches of sandy desert and provides shelter for reptiles and small mammals. After rare rains, dormant seeds burst into bloom almost overnight.
Animals have evolved specific strategies for the heat and scarcity. The greater bilby, a rabbit-sized marsupial, is nocturnal and digs deep spiral burrows to escape daytime temperatures. Its pouch opens backward so it doesn’t fill with sand while digging. Bilbies get almost all of their water from the insects and seeds they eat, rarely needing to drink. Many desert reptiles, birds, and mammals follow a similar pattern: staying underground or inactive during the hottest hours and foraging at dawn, dusk, or after dark.
The desert interior also holds cultural significance for Aboriginal Australians, who have lived in and managed these landscapes for tens of thousands of years. Many of the named deserts overlap with traditional lands where Indigenous knowledge of water sources, seasonal patterns, and land management practices remains deeply embedded.