Geography
What is a desert?
Quick answer
A desert is a place that gets very little rain, usually under 250 millimetres a year. Deserts can be hot, like the Sahara, or cold, like the Gobi and Antarctica.
In one sentence
A desert is a dry region that gets very little rain, so few plants and animals can live there.
Explained
Deserts are defined by how little water they get, not by sand or heat. A place with less than about 250 millimetres of rain a year is a desert. That includes hot ones, like the Sahara, but also cold ones like the Gobi in Asia, and even Antarctica, which is the largest desert of all.
cactus
camel
sun
Why are deserts dry? Some are far from the sea, so rain-bearing clouds rarely reach them. Some lie behind mountains that block the rain. Others sit in belts of dry, sinking air near the tropics. Many hot deserts are scorching by day and chilly at night, because there are few clouds to hold in the heat.
Only some of a desert is sand dunes. Much of it is bare rock, gravel and dry stony plains. When rain does fall, it can come in sudden floods that carve out channels called wadis. Seeds can wait for years and then bloom quickly.
Living things have clever adaptations. Cacti store water in thick stems and have spines instead of leaves. Fennec foxes have big ears to lose heat. Camels have wide feet for sand and can go a long time without drinking. Many animals hide in burrows by day and come out at night.
People live in deserts too, often near oases, where water comes up from underground. Desert regions include the Sahara and Kalahari in Africa, the Arabian Desert, the Gobi in Asia and the Outback in Australia. Deserts are part of the world's climate patterns.
Examples
| Desert | Where | Type |
|---|---|---|
| Sahara | northern Africa | hot, largest hot desert |
| Arabian | Middle East | hot |
| Gobi | China and Mongolia | cold |
| Atacama | Chile | very dry, cool |
| Antarctica | South Pole | cold, largest desert |
Common mistakes
- "All deserts are hot and sandy." Many are cold or stony.
- "Camels store water in their humps." The hump holds fat.
- "Nothing lives in a desert." Plants, animals and people have adapted.
Quick quiz
Deserts
Check what you know with 4 quick questions.
Question 1 of 4
How much rain does a desert get?
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For grown-ups
Related topics
Climate
Climate is the usual pattern of weather in a place over many years, usually 30 or more. Weather is what is happening in the sky today.
Biomes
A biome is a large region of the world with a similar climate, plants and animals. Examples are desert, rainforest, grassland, tundra and the ocean.
Africa
Africa is the world's second-largest continent, with 54 countries, the Sahara Desert, the River Nile, the Congo rainforest and savannas full of wildlife.
The Amazon River
The Amazon is a huge river in South America that carries more water than any other river on Earth. It flows about 6,400 km from the Andes across Brazil to the Atlantic Ocean.
Antarctica
Antarctica is the frozen continent around the South Pole. It is the coldest, windiest and driest continent, covered by ice, and has no permanent residents.
Asia
Asia is the largest continent, covering about a third of the world's land and holding around 60 percent of its people. It has Mount Everest, the Himalayas and the most populous countries.