Nairobi is set to step up preparations for El Niño rains after floods killed 36 people in the capital earlier this year, as the United Nations warns governments to turn early weather forecasts into action before extreme rainfall and other climate-related hazards strike.
The warning was issued during the United Nations General Assembly’s SDG Media Zone discussion, “El Niño is Here: Time to Act”, held in New York on Wednesday.
The World Meteorological Organisation says El Niño is established and is expected to persist into early 2027, with the phenomenon forecast to strengthen towards the end of this year.
WMO Secretary-General Celeste Saulo said El Niño can alter rainfall patterns and increase the likelihood of extreme temperatures thousands of kilometres from the tropical Pacific.
“El Niño begins with warming in the tropical Pacific, but its consequences are not limited to the Pacific,” Saulo said.
“Thousands of kilometres away, El Niño can shift rainfall patterns and increase the likelihood of extreme temperatures. In cities already struggling with heat, the effects reach inside homes, workplaces, schools and hospitals.”
Saulo said governments should use the warning to protect vulnerable populations and keep essential services running.
“A heat warning must therefore trigger practical measures: targeted health advice, checks on isolated people, safe cooling spaces, protection for outdoor workers, and continuity plans for electricity, water and health services,” she said.
She added: “This El Niño is a test. We have the science. We have warning. And we still have time to act.”
In Kenya, the warning comes as the country prepares for an expected wetter-than-normal October-December rainfall season.
The Kenya Meteorological Department has forecast a 99 per cent probability of above-normal rainfall during the October-December season, with the rains potentially extending into early 2027.
But Kenya Met officials have cautioned that El Niño alone does not determine the amount or distribution of rainfall in Kenya, with other climate drivers, including the Indian Ocean Dipole, also influencing the season.
That distinction is particularly important for Nairobi, which has already experienced the consequences of intense rainfall this year.
On March 6, about 160 millimetres of rain fell in one night at Wilson Airport, overwhelming drainage systems and flooding several parts of the city.
The National Police Service later reported that 36 people had died in Nairobi during the March floods, the highest number recorded in any region during the nationwide disaster, which claimed 71 lives.
Nairobi Governor Johnson Sakaja said the intensity of the rainfall demonstrated the challenge facing the capital when large volumes of water fall within a short period.
“If you look at the rains on March 6th earlier this year, 160 mm in one night is what happens in many days. When it happens at a go, that's when we have a sudden challenge,” Sakaja said.
He said Nairobi’s flood vulnerability is also linked to the division of responsibilities and financing for roads and drainage infrastructure.
“Tell me the places you know that flood. Name me a road. Nairobi Expressway. That is under KeNHA, National Government. Waiyaki Way, KeNHA. Thika Road, National Government,” he said.
“In this country, 60% to 70% actually are county roads. But counties don't get that money. Financing follows functions.”
Sakaja said resources should follow the responsibilities assigned to counties under the Constitution.
“If the functions in the Fourth Schedule of our Constitution are what the county must do, give the county that money to do it,” he said.
“You cannot have the money and then chisel your fingers as the blame goes elsewhere.”
The governor said children and residents of informal settlements remain particularly vulnerable when rivers overflow and drainage systems are overwhelmed.
“The first people you think about when you think about such an event happening are children. And how will children be taken care of?” Sakaja said.
He said Nairobi’s historical settlement patterns had also contributed to the exposure of communities living close to rivers.
“If you look at the 1928 master plan, they created what we call green buffer zones, which are close to the rivers, because they wanted to segregate themselves from Africans. These green buffer zones became slums, informal settlements,” he said.
Sakaja said communities living in areas such as Kibra, Mukuru, Mathare and Korogocho are among those exposed when flooding occurs.
“And so that is why whenever there's big flooding, who is affected? Kibra, Mukuru, Mathare, Korogocho. All of them are along that,” he said.
The governor said the county had started issuing early warnings and would identify residents in high-risk areas for possible evacuation.
“This time, we've given the warnings early,” he said.
“We'll have notices, the sub-counties with the wards. There's a cut-off by which we will just come and have you.”
Nairobi has also accelerated drainage works, river desilting and other flood-control measures in identified hotspots ahead of the rains.
The county has a Sh2.4 billion flood-mitigation programme covering drainage works, river desilting and outfall drains, while engineers and contractors have been directed to accelerate critical works before the rains intensify.
The Kenya Maritime Authority has also issued a safety warning covering the September-December period, cautioning coastal communities, fishermen and vessel operators about potentially rough seas, strong winds, high waves, heavy rainfall and poor visibility.
The wider warnings come against a backdrop of Kenya’s experience with previous El Niño events.
The 1997-98 El Niño was associated with some of the most severe flooding in Kenya’s recorded history, while the 2023 El Niño floods killed more than 100 people and displaced more than 500,000, according to UN Kenya.
The UN says the current event should not automatically be treated as a repeat of either episode because El Niño’s effects vary by region and are influenced by other climate drivers.
