Nepedia
Back to Discover
Advanced Reader
🗺️

Sahara

geography Maturity 7-9 Vital Level 3 Next article →

The Sahara is the world's largest hot desert.

Sahara satellite hires
Sahara satellite hires

It spans a massive portion of North Africa. This region covers about 31% of the African continent. It is the third-largest desert on Earth. Only the cold deserts of Antarctica and the Arctic are larger. The name "Sahara" comes from the Arabic word for "desert."

Saharan topographic elements map
Saharan topographic elements map

It stretches from the Mediterranean Sea in the north to the Atlantic Ocean in the west. To the east, it reaches the Red Sea. To the south, it meets the Sahel. The Sahel is a belt of semi-arid tropical savanna. This belt surrounds the Niger River valley and the Sudan region.

The climate of the Sahara is driven by complex atmospheric systems. The desert sits in the horse latitudes under a subtropical ridge. This is a belt of semi-permanent, warm-core high pressure. In this zone, air from the upper troposphere descends toward the ground. This descending air warms and dries the lower atmosphere. This process prevents clouds from forming. Without clouds, there is very little rainfall. The atmosphere remains stable and prevents convective overturning. This results in weather that is sunny, dry, and stable. The prevailing air mass is the continental tropical air mass. This air is both hot and dry. It forms over the vast heating of the North African land. The Sahara High is an extension of the Azores High. This high-pressure system blocks rain-bearing weather systems from entering the region.

The landscape of the Sahara is highly diverse. It is not just a single type of terrain. The desert includes hamada, which are rocky plateaus. It also features ergs, or large sand seas covered in dunes.

Algeria Sahara Desert Photo From Drone 5
Algeria Sahara Desert Photo From Drone 5

You can find gravel plains known as reg. There are dry valleys called wadis and dry lakes. Some areas contain salt flats called shatt or chott. The desert also has many mountain massifs and volcanic uplands. Some mountains are deeply dissected. The Aïr Mountains and the Tibesti Mountains are notable examples. The highest peak is Emi Koussi. This is a shield volcano in the Tibesti range of northern Chad.

Hoggar8
Hoggar8

The desert also contains unusual landforms like the Richat Structure in Mauritania.

Temperature extremes are a defining feature of the Sahara. The high position of the Sun creates intense heat. The lack of vegetation and clouds makes it the hottest large region in the world. In the summer, average high temperatures exceed 104 degrees Fahrenheit in many spots. Some areas in southern central parts see highs above 113 degrees Fahrenheit.

Sunset in Sahara
Sunset in Sahara

The sand can become incredibly hot during the day. Temperatures on the sand can reach 158 degrees Fahrenheit. In some places, ground temperatures have reached 176 degrees Fahrenheit. The sky is extremely clear. Most of the desert receives over 3,600 hours of bright sunshine annually. In the eastern part, it can exceed 4,000 hours. However, the lack of humidity causes high diurnal temperature variations. This means the temperature changes significantly between day and night. While nights are cooler, they can drop to freezing in high-elevation areas during winter.

The Sahara has undergone major changes over long periods. It has not always been a dry desert. For several hundred thousand years, the region has cycled between desert and savanna. This cycle lasts about 20,000 years. The cause is the precession of Earth's axis. This is the wobble of the Earth as it rotates around the Sun. This wobble changes the location of the North African monsoon.

These shifts determine whether the region is a grassland or a desert. This history shows how much the African landscape can change over time.

Life in the Sahara is often found near water or at its edges. In the hyperarid central regions, vegetation is very sparse. However, moisture collects in wadis to support trees and shrubs. Oases provide vital spots for life in the dry landscape.

Hoggar8
Hoggar8

The northern limit of the desert is marked by the limit of date palm cultivation. The southern limit is marked by the grass Cenchrus biflorus. Many important cities are located within or near the desert. These include Nouakchott in Mauritania and Timbuktu in Mali.

Ghardaia01
Ghardaia01

Other cities include Agadez in Niger and Ghat in Libya. These places serve as important hubs in a vast, challenging environment.

The Sahara is a vital part of the Earth's geographic and climatic systems. It is one of three distinct physiographic provinces of the African massive. The desert is so large and bright that it could be detected from other stars. This is possible with near-current technology. The extreme aridity is also enhanced by the Atlas Mountains. These mountains create a rain shadow effect. They block humidity from the Mediterranean from reaching the northern desert. This interaction between mountains, air pressure, and geography creates one of the most unique environments on our planet.

803 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (24)
File:Vegetation Africa.png
Vegetation Africa.png
File:Sahara satellite hires.jpg
Sahara satellite hires.jpg
File:Hoggar8.jpg
Hoggar8.jpg
File:Algeria Sahara Desert Photo From Drone 5.jpg
Algeria Sahara Desert Photo From Drone 5.jpg
File:Sunset in Sahara.jpg
Sunset in Sahara.jpg
File:Journal.pone.0076514.g004.png
Journal.pone.0076514.g004.png
File:Village Telly in Mali.jpg
Village Telly in Mali.jpg
File:Great green wall map.svg
Great green wall map.svg
File:Saharan topographic elements map.png
Saharan topographic elements map.png
File:GueltaCamels.jpg
GueltaCamels.jpg
File:Libya 5391 Ubari Lakes Luca Galuzzi 2007.jpg
Libya 5391 Ubari Lakes Luca Galuzzi 2007.jpg
File:Mathendous giraffes.jpg
Mathendous giraffes.jpg

+ 12 more

More to explore

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.