Azania Front Lutheran Church with the harbor in th
Azania Front Lutheran Church with the harbor in the background, Dar es Salaam, Tanzania. (Photo by: Education Images/Universal Images Group via Getty Images)
  • The world's projected fastest-growing cities based on UN population estimates are all in Africa.
  • The United Nations publishes annual population projections for future years, and we looked at the cities with the biggest projected growth by 2035.
  • Among the fastest-growing cities are three cities located in Tanzania.
  • For more stories go to www.BusinessInsider.co.za.

The world population is expected to grow to 8.6 billion in 2030, and African metro areas are leading this growth.

According to a 2017 UN press release, population growth will mainly occur in nine countries, including five African countries - Tanzania, Congo, Uganda, Nigeria, and Ethiopia. The 15 fastest-growing cities, all located in Africa, are projected to almost double their populations by 2035.

Africa is growing so quickly because of its increasingly large young population, the highest of any continent. Over 75% of its population is younger than 35, according to the United Nations Office on the Special Adviser of Africa.

The United Nations Department of Economic and Social Affairs publishes population estimates using data from national censuses and specialised population surveys. We examined the cities that are projected to most rapidly grow in size over the next 15 years among urban areas that had at least 300,000 residents as of 2018 based on the UN's projections of 2020 and 2035 city populations.

Here are the 15 fastest-growing global cities and their expected change in population:


15. Lilongwe, Malawi, has an estimated 2020 population of 1,122,000 and is projected to grow by 97% to 2,210,000 in 2035.

MALAWI MAY 6(SOUTH AFRICA OUT): Bicycle taxi driv
Bicycle taxi drivers wait for passengers in Mponela Village on May 6, 2015 in Malawi. Bicycle taxis known as kabazas in Chichewa, are a cheaper form of transport for village people who cant afford taxis. Fares start from 100 kwacha about R2, 50 and increase in price, depending on the passengers distance. (Photo by Thulani Mbele/Sowetan/Gallo Images/Getty Images)

14. Ouagadougou, Burkina Faso, has an estimated 2020 population of 2,780,000 and is projected to grow by 97% to 5,481,000 in 2035.

OUAGADOUGOU, BURKINA FASO - JANUARY 18: A soccer f
(Photo by Olympia De Maismont/Anadolu Agency/Getty Images)

13. Uige, Angola, has an estimated 2020 population of 511,000 and is projected to grow by 98% to 1,013,000 in 2035.

Angola
Getty Images

12. Bobo-Dioulasso, Burkina Faso, has an estimated 2020 population of 972,000 and is projected to grow by 100% to 1,940,000 in 2035.

Train Station, Bobodioulasso, Burkina Faso, Design
Train Station, Bobodioulasso, Burkina Faso, Designed By French Colonialists. (Photo by: Education Images/Universal Images Group via Getty Images)

11. Dar es Salaam, Tanzania, has an estimated 2020 population of 6,702,000 and is projected to grow by 100% to 13,383,000 in 2035.

Azania Front Lutheran Church with the harbor in th
Azania Front Lutheran Church with the harbor in the background, Dar es Salaam, Tanzania. (Photo by: Education Images/Universal Images Group via Getty Images)

10. Tete, Mozambique, has an estimated 2020 population of 371,000 and is projected to grow by 101% to 744,000 in 2035.

Mozambique
Getty Images

9. Niamey, Niger, has an estimated 2020 population of 1,292,000 and is projected to grow by 101% to 2,600,000 in 2035.

NIAMEY, NIGER - OCTOBER 3: Women buy herbs in the
Women buy herbs in the market, as Nigeriens struggle to cope with the challenges of daily life in the second-poorest country in the world, made worse by increased strains from tens of thousands of would-be migrants to Europe increasingly being prevented from traveling north across the Sahara, as well as forced returns from Algeria and Libya, on October 3, 2018 in Niamey, Niger. The Sahelian country on the southern edge of the Sahara Desert has become a security focus for both the US and Europe, in their bid to stem migration flows and also combat Islamic State and Al Qaeda jihadists in West Africa. (Photo by Scott Peterson/Getty Images)

8. Bunia, Congo, has an estimated 2020 population of 679,000 and is projected to grow by 101% to 1,368,000 in 2035.

BUNIA, DEMOCRATIC REPUBLIC OF CONGO - DECEMBER 12:
A group of boys wave in the Bunia AIRO refugee camp near Bunia airport on December 12, 2004 in Bunia, Democratic Republic of Congo. Approximately 13000 refugees have found refuge in the camp. United Nations peacekeepers in Congo have made an urgent appeal for militias to cease fighting in the east.(Photo by Mark Renders/Getty Images)

7. Gwagwalada, Nigeria, has an estimated 2020 population of 410,000 and is projected to grow by 102% to 827,000 in 2035.

A view of a flooded area after torrential rain caused flood at Gwagwalada district of Abuja, Nigeria on September 12, 2016. (Photo by Henry Chukwuedo/Anadolu Agency/Getty Images)

6. Mwanza, Tanzania, has an estimated 2020 population of 1,120,000 and is projected to grow by 102% to 2,267,000 in 2035.

Tanzania, Mwanza, residential building on Lake Vic
Tanzania, Mwanza, residential building on Lake Victoria shoreline

5. Songea, Tanzania, has an estimated 2020 population of 353,000 and is projected to grow by 110% to 740,000 in 2035.

Tanzania
Getty Images

4. Kabinda, Congo, has an estimated 2020 population of 466,000 and is projected to grow by 110% to 979,000 in 2035.

PRETORIA, SOUTH AFRICA - MARCH 9: A protester hold
Photo by Ihsaan Haffejee/Anadolu Agency/Getty Images

3. Kampala, Uganda, has an estimated 2020 population of 3,928,000 and is projected to grow by 112% to 7,004,000 in 2035.

KAMPALA, UGANDA - 2018/01/30: Cars and boda bodas
Cars and boda bodas drive along Riga Street, Kampala.

2. Zinder, Niger, has an estimated 2020 population of 489,000 and is projected to grow by 118% to 1,065,000 in 2035.

(GERMANY OUT) NER. Niger, Zinder. Fahrgaeste am Bu
Photo by Markus Matzel/ullstein bild via Getty Images

1. Bujumbura, Burundi, has an estimated 2020 population of 1,013,000 and is projected to grow by 123% to 2,263,000 in 2035.

BUJUMBURA, BURUNDI - MARCH 04: Scores of people ga
Photo by Renovat Ndabashinze/Anadolu Agency/Getty Images

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