Kenya's El Niño short rains due mid-October as Nairobi riparian clearances continue

Kenya's short rains are due to start in most parts of the country in the second and third weeks of October, and the forecast points to a strong El Niño. The Kenya Meteorological Service Authority (Kenya Met) expects above-average rainfall across about 80 per cent of the country, so Nairobi's river corridors and informal settlements are again the main worry.

According to Kenya Met's October–December 2026 outlook, rain will continue in western Kenya and begin in other parts of the country in the second and third weeks of October. The season is expected to bring prolonged wet spells and occasional isolated storms.

What forecasters say

In an August forecast reported by The Star, Kenya Met put an 81 per cent probability on the 2026 El Niño being very strong, and a 97 per cent chance it would persist into early 2027. The World Meteorological Organization, quoted in a Star big read in late September, says El Niño is "firmly established", with a near 100 per cent likelihood of lasting through February 2027.

Stanley Kinyua, Kenya Met's Narok County Director of Meteorological Services, cautioned that El Niño strength alone does not decide how much rain falls. The Indian Ocean Dipole also matters, he said. He noted that the 2015 El Niño, though very strong, brought less rain than 1997 because "the IOD was weakly positive".

El Niño has caused major flooding in Kenya in 1997–1998, 2006–2007, 2015–2016 and 2023–2024, according to The Star. The Star says the most recent episode brought floods and landslides that killed hundreds.

Nairobi's weak points

The news site Education News lists Mathare, Korogocho, Lucky Summer, Kibera, Kawangware, Kangemi, Dandora, Kariobangi, Kayole and Ruai among the Nairobi areas close to rivers, drainage channels, floodplains and low-lying ground that face potential flooding.

The National Disaster Operations Centre, under the Ministry of Interior and National Administration, is responsible for coordinating information and response during disasters. Its director, Col (Rtd) David Samoei, said in the Star piece that "the first line of defence is not a rescue boat deployed after a river has burst its banks. It is an accurate warning delivered early, understood locally and acted upon before danger arrives."

The plan calls for clearing drains, waterways and culverts in urban areas and inspecting bridges, culverts and flood-prone highway sections. The Kenya Defence Forces and National Youth Service are to provide search-and-rescue, engineering and logistics support if civilian capacity is exceeded. Members of the public can report incidents through the centre's toll-free number, 0800 721 571.

Riparian clearances and a disputed case

The preparations overlap with a long-running push to clear buildings from riparian land, the protected strip beside rivers. In March 2026 multi-agency teams worked along the Nairobi and Ngong rivers, The Standard reported, clearing structures on riparian land ahead of heavy rains. In May, Nairobi Rivers Commission Commissioner Mumo Musava said on Citizen TV that the commission had issued over 300 notices along the Nairobi River and its tributary, Kirichwa Kubwa, according to Kenyans.co.ke. He said the commission must follow fair administrative action, including public participation.

Not every clearance is accepted. Residents of Willow Court, an apartment estate in Nairobi West, say demolition along the Ngong River continued this week despite a temporary injunction from the Water Tribunal. Kenya Today and Uzalendo News, both reporting on 1 October 2026, carry the residents' account. The two reports are very similar, so they may rest on the same residents' statement.

According to those reports, the tribunal's order of 7 May 2026 restrains Nairobi City County and other respondents from demolishing structures on land parcel L.R. No. 37/750. Residents say sections of boundary walls and concrete flooring have been removed. They also fear for the structural integrity of a connecting bridge and for flooding risks.

The residents argue that the apartments, built about 18 years ago, had an Environmental Impact Assessment licence dated 10 August 2007 and kept a 10-metre riparian setback. They also say the Water Resources Authority measured from property boundaries, not the high-water mark, and that applying the 2025 Water Resources Regulations to a development approved between 2007 and 2009 amounts to retrospective application of the law. These are the residents' claims and we have not independently verified them.

The Water Resources Authority told the tribunal it had not yet filed its response and intended to carry out a site verification, to which residents' representatives would be invited. The tribunal sat on 1 October 2026 to confirm the status of responses. We found no response from Nairobi City County.

What happens next

The rains are due to begin in the second and third weeks of October, so there is little time left for drain clearing and evacuation planning. County commissioners have been told to convene governors, disaster teams, security and health officials, road authorities and the Kenya Red Cross, according to the Star article.

Health agencies are expected to strengthen surveillance, since flooding raises the risk of cholera, malaria, Rift Valley fever and chikungunya. The Food and Agriculture Organization and World Food Programme have appealed for US$202 million (about KES 26 billion, as converted by The Star) for vulnerable communities across the 22 countries at risk, including Kenya.

Analysis: the Willow Court dispute shows the tension in the plan. Authorities want river reserves cleared before the rains, while some owners say the legal basis is contested. How the tribunal rules may shape how fast clearances proceed in the coming weeks.