Largest Deserts in the World

Data

Source: Wikipedia — List of deserts by area.

Note: What You Should Know About the World's Largest Deserts

You probably picture rolling sand dunes when you hear "desert," but a desert doesn't actually have to be sandy at all. By definition, a desert is a region that gets very little precipitation — generally less than about 250 mm of rain per year — and loses more moisture through evaporation than it gains. What matters is the lack of water, not the scenery. That's why the two biggest deserts on Earth are made almost entirely of ice.

What the rankings really tell us

• The champion is Antarctica. The Antarctic Desert covers about 14.2 million km² — an entire continent of ice and rock — and holds the record for the driest conditions on the planet. Some parts of it have seen no meaningful rain or snow for years.
• Number two is the Arctic. At roughly 13.99 million km², the Arctic Desert is nearly a match for Antarctica. It's a polar desert made up of sea ice and the frozen lands of places like Greenland, northern Canada, and Siberia.
• The largest hot desert is the Sahara. Covering about 9.2 million km², the Sahara stretches across much of North Africa — and it's still growing southward as the climate changes.
• The Arabian Desert (about 2.33 million km²) spans the Arabian Peninsula, bringing scorching summers and famous sand seas to the Middle East.
• The Gobi (about 1.3 million km²) is a "cold winter" desert straddling China and Mongolia — it gets frost and snow despite being a desert.
• The Kalahari (about 900,000 km²) covers much of southern Africa and is partly a "green" desert — it gets more rain than some siblings and is grazed by wildlife.

The main types of deserts

• Hot (subtropical) deserts — high daytime temperatures, scorching sun, and very little rain. Think Sahara, Arabian, and Kalahari.
• Cold winter deserts — baking-hot summers but freezing winters with snow. The Gobi and Patagonian desert fit this label.
• Coastal deserts — located along shores where cool ocean air keeps rainfall extremely low, like the Atacama in South America.
• Polar deserts — the extremists of the family. They're nearly always below freezing, so moisture is locked up as ice rather than falling as rain. Antarctica and the Arctic are the two giants here.

A few handy tips

• When comparing "largest deserts," always check the definition the list uses — many sources rank polar deserts at the top, while simpler lists only count sandy hot deserts and put the Sahara number one.
• Precipitation is the honest yardstick. A region that's hot doesn't necessarily mean dry, and a cold one isn't automatically wet — rain (or snow) totals are what sort real deserts from non-deserts.
• Deserts are not lifeless. Even the Sahara and the Antarctic host hardy plants, insects, birds, and mammals that have adapted to extremely little water.
• "Desertification" is a real risk: human activity and climate change are turning more dry lands into true deserts each year.

Fun facts

• Antarctica holds the record for the driest place on the planet — the McMurdo Dry Valleys, which may not have seen rain for roughly two million years.
• About one-third of Earth's land surface is covered by deserts or semi-deserts — far more than just the sandy boxes on most maps.
• The Sahara is roughly the same size as the whole United States and grows larger every year.
• The Gobi isn't sandy like you'd imagine in spots — much of it is rocky, gravel-covered steppe.
• Polar deserts cover more land than all the world's hot deserts combined.
• Plants in hot deserts often survive decades without rain by storing water, like cacti, or by sprouting only in rare full bloom years, like the desert wildflowers.
• Both Antarctica and the Arctic are considered deserts precisely because their skies deliver so little precipitation each year.

Whether it's a frozen frontier or a sun-baked sea of sand, every desert shares one thing in common: water is scarce, and life has to be clever to survive. The next time you look at a "largest deserts" chart, remember — the true heavyweights are frozen, not hot.