For a place to be considered as a desert it has to
have a yearly rainfall of 10 inches or less.
Antarctica is the largest desert on Earth even
though it is cold and icy.
The Sahara is the hottest desert on Earth and has
an average yearly rainfall of 3.9 inches.
Deserts cover about 1/5th of the Earths surface.
There are five major types of
deserts, dry, hot, semiarid, coastal and cold.
Deserts are formed when a place receives
minimal amounts of precipitation.
Some deserts can be found on the west coasts of
continents right next to the ocean. Even though
they are near water little precipitation occurs
because the water is colder than on the east
coast meaning the water is less likely to be
Hot and Dry Deserts
The seasons are generally warm and very hot in the
summer. Winter usually brings very little rainfall.
Desert surfaces receive nearly twice as much solar
radiation than humid environments and lose almost
twice as much heat after the sun goes down.
Rainfall is usually very low and/or concentrated in
short bursts between long rainless periods.
Evaporation rates normally exceed rainfall rates.
The soil is course-textured and rocky/gravely and
has no subsurface water. The reason for the dirt
been so coarse is that the finer dust particles get
blown away elsewhere leaving larger pieces of rock
Summer is moderately long and dry. Like hot
deserts winter brings very little rainfall. Summer
temperatures average about 21-27˚C and
normally does not go above 38˚C.
The average annual rainfall for semiarid deserts is
2-4cm. The condensation of dew at night may
equal or exceed the rainfall received by some
The soil can range from sandy and fine-textured
to loose rock fragments, gravel and sand.
Semiarid deserts have no subsurface water
Cold deserts are recognised by cold winters and
snowfall with high overall rainfall in the winter and
occasionally in the summer. The winter
temperature ranges from -2 to 4˚C and the
summer temperature ranges from 21 to 26˚C.
In the winter there is quite a bit of snow and the
most amount of rain is received in either April or
May. The soil is heavy, silty and salty but due to
good drainage there is only a little bit of salt.
Coastal deserts are found in warm areas such as
Nearctic and Netropical realms. Winter is very
cold with 5˚C and below and is followed by a
moderately long summer with temperatures
ranging from 13-24˚C.
The average annual rainfall is 8-13cm in most
areas. This low amount of rainfall makes the soil
fine-textured with a moderate salt content. Some
plants have long roots close to the surface so
that they can take advantage of the low rainfall.
Deserts are places that have very minimal
rainfall. People think that deserts are hot and dry
places with sand everywhere but deserts
climates are much more complex. They can be
cold, icy, hot, dry, rocky and windy.
Deserts occur in places like the north and south
poles, inland areas, coasts and sometimes in
Desertification is the process by which fertile land
becomes desert, typically as a result of
drought, deforestation, or overuse of land for
In some deserts there is a layer of rock that stores
water, this is called an aquifer. When you see an
oasis in the desert the water is coming from the
aquifer and supplying the plants with water.
Flora and Fauna
There are many special and interesting types of
plants and animals that inhabit deserts. These
plants and animals have evolved over time so
they are able to survive in the harsh conditions of
When you think of a deserts you think of sand
dunes but did you know that there are lots of
different types of sand dunes and desert
landforms. Some of these include, pedestal
rocks, star dunes, barchan dunes, mesas and