Fast-growing African cities, including Kenya‘s capital city Nairobi, are experiencing what scientists describe as ‘climate whiplash’ – a phenomenon that causes dramatic shifts in flooding and droughts.

These extreme weather conditions pose a risk for urban populations and prevent communities from accessing clean water worldwide, according to a new study released last week by the non-profit WaterAid, the world’s leading water, sanitation and hygiene charity. Since 1981, WaterAid programmes have reached 28.9 million people with clean water, 29.2 million with decent toilets and 28.7 million with good hygiene.

In the report ‘Water and Climate: Rising Risks for Urban Populations’, WaterAid unveils cities across Africa and Asia that are emerging as the most-at-risk to extreme climate shifts worldwide. This will in turn have devastating impacts on access to clean water for urban communities on the frontline of climate change.

The report reveals regional wetting hotspots in Southern Asian cities, widespread drying throughout European cities, and ‘climate whiplash’ trends across four continents including Africa.

Published on March 12, 2025, WaterAid’s new research reveals which of the world’s 100 most populated cities are becoming increasingly exposed to floods and droughts – risking the security and survival of communities around the world.

Almost 1 in 5 (15 per cent) of cities studied emerge as experiencing ‘climate whiplash’ – intensification of both droughts and floods – whereas 20 per cent of cities have seen a major flip from one extreme to the other.
Cities in Southern Asia are becoming overwhelmingly flood-prone and European cities are exhibiting significant drying trends, all of which can impact people’s clean water access and water security.

From recent droughts in cities like Madrid in Spain and Cape Town in South Africa, to large-scale flooding across cities in Bangladesh and Pakistan, 90 per cent of all climate disasters are driven by too little or too much water.

More frequent

WaterAid warns that weather-related disasters such as flooding and drought have increased by 400 per cent in the last 50 years, putting major pressure on vital water access and sanitation systems. This makes is harder for communities and economies to prepare for, recover from and adapt to climate change.

In East Africa, more severe droughts are giving way to heavier floods, a back-to-back pattern that is becoming more pronounced, with three capital cities – Addis Ababa in Ethiopia, Kampala in Uganda and Nairobi in Kenya – experiencing this so-called “climate whiplash” mentioned in the WaterAid report.

The phenomenon, also affecting Cape Town, sees prolonged droughts that can cause water shortages, food insecurity and electricity disruptions interspersed with intense rainfall, overwhelming urban drainage and resulting in flash floods that displace communities, damage roads and spread waterborne diseases.

Sudan’s capital Khartoum and Cameroon’s capital Yaoundé, meanwhile are experiencing a flip in their prevailing climate trends from wet to dry extremes, with the opposite happening in the Nigerian city of Kano, the study found.

Writing in the authoritative UK-based Climate Home News, Vivian Chime said climate change is intensifying in South Africa, while a separate study showed some of the continent’s biggest cities are being squeezed by wet and dry extremes.

Last month, Chime reported, southern Botswana and eastern South Africa suffered five consecutive days of heavy rainfall that caused severe flooding across the region, killing at least 31 people, including six children, and displacing about 5,000 others.

Such episodes are becoming more frequent in a warming word, scientists working with the World Weather Attribution (WWA) group, based in Botswana, Denmark, South Africa, the UK, the US and elsewhere told Climate Home News, an award-winning independent digital publication reporting on the international politics of the climate crisis.

Alongside heavier precipitation, a key driver of disasters in cities is inadequate infrastructure, they said.

For instance, in Botswana’s capital Gaborone, drainage systems have not kept pace with its growing population density and fast-expanding construction, making low-lying areas particularly susceptible to severe flooding.

Climate change

With today’s global warming of 1.3 degrees Celsius, a warmer atmosphere is holding more moisture and leading to more extreme downpours, said Ben Clarke, one of the WWA research authors.

“To limit the damage, we need to cut fossil fuel emissions and adapt to a warmer climate,” he added.

Piet Kenabatho, a professor of environmental studies at the University of Botswana told Climate Home News that investment in better storm water management systems “is more than urgent” if Botswana is to cope with the effects of climate change.

Chime noted that while the researchers could not quantify the precise contribution of climate change to February’s flooding, they said historical weather observations show an increasing trend in five-day rainfall over the last few decades.

Based on the data, they estimated that similar rainfall events are about 60 per cent more intense today than in pre-industrial times, before humans started burning fossil fuels.

Clarke warned that climate models show the situation will become even more dangerous in the future. To understand the broader implications for Botswana and its development, Tiro Nkemelang, of the Botswana Institute of Technology Research, called for more investment to study weather and climate.

The pioneering new WaterAid study, developed with academics from University of Bristol and Cardiff University, compares each city’s social and water infrastructure vulnerabilities alongside 40-plus years’ worth of new data on climate hazards – concluding which cities and communities worldwide are the most vulnerable to extreme climate changes and the least equipped to handle them.

Heightened risks

The vulnerabilities the report examines range from poverty to poor water and waste systems, exposing ever-expanding urban populations at risk to intensifying floods or droughts, leading to displacement, instability and loss of life.

Severe urban flooding can damage sanitation facilities, spreading diseases such as cholera and typhoid, whilst water shortages during droughts are leaving millions of families without the water they need to survive.

Among the report’s top findings are that 20 per cent of the cities studied are experiencing dramatic shifts to extreme wet or extreme dry conditions, referred to as ‘climate hazard’ flips. Approximately 13 per cent are flipping toward a more extreme wet climate, while about 7 per cent are flipping to a more extreme dry climate.

This amounts to over a quarter of a billion people across the world experiencing a major flip in their climate, including cities such as Kano (Nigeria), Bogota (Colombia) and Cairo (Egypt), placing major pressure on access to safe and clean water.

South and Southeast Asia emerges as a regional hotspot, with Colombo (Sri Lanka), Faisalabad (Pakistan), and Lahore (Pakistan) seeing the most dramatic flip from historically dry conditions to become severely flood prone.

The report also reveals that 17 cities across multiple continents, 15 per cent of the cases studied, are experiencing an intensification of both extreme floods and droughts, known as ‘climate whiplash’, including Addis Ababa (Ethiopia), Hangzhou (China), and Jakarta (Indonesia).

By looking at social and infrastructural vulnerability alongside the climate data, the report hotspots heightened risk in two key regions: South and Southeast Asia and North and East Africa. The cities identified as the most vulnerable include Addis Ababa (Ethiopia), Baghdad (Iraq), Faisalabad (Pakistan), Khartoum (Sudan), Lahore (Pakistan), Nairobi (Kenya) and Surabaya (Indonesia).