From Simple English Wikipedia, the free encyclopedia
Regions with desert climates
BWk
(cold desert climate)
Desert climate
or
Arid climate
(in the
Koppen climate classification
: BWh "hot desert climate" and BWk "cold desert climate") is a type of
climate
where
precipitation
is generally less than 250 millimetres (10 in) a year.
[1]
Low rainfall is a
feature
of deserts such as the
Arabian
, central
Australia
and the
Sahara
. It is a feature of
continental
interiors
, the western sides of continents, and the
leeward
side of tall
mountain ranges
.
[1]
Parts of the
Arctic
and
Antarctic
have arid climates even though they are cold.
[1]
A "true desert" is one where plant cover is very sparse and rainfall is rare or infrequent.
[2]
Because desert air is dry there is little
moisture
to hold onto the heat of the day.
[3]
Desert nights are usually very cold. This wide temperature variation can make a desert climate difficult to live in.
[3]
Some deserts get more than 250mm of rainfall yearly but are still arid areas. For example, the
Kalahari Desert
gets up to 640 millimetres (25 in) a year.
[4]
It has great
sand dunes
like the Sahara, but they do not shift in the
winds
. They have plants that anchor the sand and help to keep their shape. Other areas can also have more than 250mm of precipitation but lose more water via
evapotranspiration
than falls as
precipitation
.
Tucson
and
Alice Springs
are good examples of this. Tucson gets an average of 303 millimetres (12 in) of
rainfall
a year.
[5]
Alice Springs receives about 540 millimetres (21 in) yearly. Some
scientists
do not consider these as true deserts.
There are three types of desert climates in the
Koppen climate classification
: a hot desert climate (BWh), a cold desert climate (BWk) and a mild desert climate (BWh/BWn). Hot deserts have very hot
summers
that have
temperatures
that can even reach 45 °C (113 °F). Temperatures can even be very warm during
winter
. Cold deserts can have hot summers as well, but the winters are usually very cold. They are usually at high
altitudes
and can be drier than hot deserts.
![](//upload.wikimedia.org/wikipedia/commons/thumb/c/c0/Detail_of_cactus_%22Saguaros%2C_Saguro_National_Monument%2C%22_Arizona._%28Vertical_Orientation%29%2C_1933_-_1942_-_NARA_-_519974.jpg/120px-Detail_of_cactus_%22Saguaros%2C_Saguro_National_Monument%2C%22_Arizona._%28Vertical_Orientation%29%2C_1933_-_1942_-_NARA_-_519974.jpg)
Saguro cactus
Desert
plants
and
animals
have adapted to living in desert climates.
[6]
Some animals can get by on less water. Some plants are able to store water.
[6]
Some animals, like
snakes
,
lizards
and
scorpions
use
poisonous
venoms
to kill for food.
[3]
This saves valuable
energy
: they do not need to chase, fight or catch their
prey
.
[3]
Many
animals are nocturnal
. They sleep in cool
caves
or
burrows
during the day and hunt at night.
[3]
Plants likewise have adapted to saving water. Some have
waterproof
coverings that prevent the plant or seeds from drying out. Some, like the giant
Saguaro
cactus
, store water. They have adapted so well that they can live for more than 150 years and can average over 40 ft tall.
[7]
Many types have
thorns
and
protective spines
that keep animals from getting at their stores of water.
[3]