World's second largest continent
Africa is the second largest continent, approximately three times the size of the United States. The African continent measures 5,200 miles from north to south, and at its broadest point, is nearly as wide as it is long.
Africa contains both the world’s largest desert (the Sahara) and the world's longest river (the Nile). The continent is also home to Victoria Falls (pictured above), considered as one of the natural wonders of the world.
Africa’s 11,636,846 square miles of land are divided into 55 countries (including South Sudan, which became a separate country in 2011).
Africa is bordered by:
- the Atlantic Ocean to the west
- the Indian Ocean to the east
- the Mediterranean to the north.
A variety of climate zones
Unsurprisingly, such a large land mass has a wide variety of climates:
- Tropical rainforest – found particularly in the centre of the continent and also along the eastern coast of Madagascar.
- Humid sub-tropical – found in the southwest.
- Mediterranean – mostly on the northwest (Mediterranean) coast and in the southeast
- Savannah – found to the north and south where it replaces the rain forest. There are distinct wet and dry seasons.
- Steppe – away from the Equator, to the north and south, the savannah grades into drier steppe.
- Desert – here there is little rainfall and wide differences between day and night temperatures. The Sahara in the north is the world’s largest desert (only three countries have a greater area – Russia, Canada and China). The Kalahari in southern Africa covers an area larger than France.
- Highland – largely found in the east, below the Horn of Africa.
- Marine – largely in the southeast.
The highest temperature recorded anywhere in the world was at Al’Aziziya, Libya, which reached 57.8°C (136°F) on September 13, 1922. The lowest recorded temperature in Africa is -24°C (-11°F) at Ilfrane, Morocco, on February 11, 1935.
Highs and lows
Temperatures are highest in desert areas, particularly the Sahara. They are coolest across the south and in mountainous areas and plateaux highlands.
Rainfall varies dramatically across Africa. The northern half of the continent contains large areas of arid desert, where annual rainfall can be just 50mm. But in central areas of the continent, tropical rainforests can receive over 4,000mm each year (Scotland has an average of around 1,500mm).
An encroaching desert
As the climate warms, the Sahara desert is thought to be advancing south at a rate of 600 metres each year. Deforested areas are more at risk; where trees have been cleared for farm land or burning wood, bare earth is blown away and replaced by sand. This process is known as 'desertification'.
Changing weather patterns
However, patterns of weather are changing, both locally and across the continent.
For example, droughts are becoming more common across the semi-arid Sahel region (which stretches across countries such as Senegal, Mauritania, Mali, Niger, Chad and Sudan). Scientists think a rise in water temperatures in the nearby Gulf of Guinea has shifted the flow of rain clouds southwards.
Each year, the rainbelt moves northwards up into sub-Saharan Africa (by around August), and then moves back southwards into sub-central Africa (by March). Equatorial Africa remains in the rainbelt throughout the year, which is why this region is the wettest part of the continent.