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Heavy rains and rising floods: Climate experts explain the sudden surge
Submerged homesteads in Nyong'ong'a Sub Location in Nyakach, Kisumu County on March 7, 2026.
Kenya is currently in the March–April–May (MAM) long rains season, typically marked by widespread rainfall and thunderstorms across most parts of the country.
Since late February 2026, many regions, including the Lake Victoria Basin, the Rift Valley, the western and central highlands (encompassing Nairobi), and parts of the coast and southeastern lowlands, have experienced intensified downpours, with several days recording more than 20 mm of rainfall within 24 hours. This has led to flooding, flash floods, and landslides in vulnerable areas.
According to the Ministry of Interior, at least 110 people have died as floods continue to devastate large parts of the country, with the crisis now affecting 30 counties. Nairobi has recorded the highest number of fatalities at 37, followed by the Eastern region with 26 deaths, while the Rift Valley has reported 14. Nyanza has recorded 11 fatalities, Central six, the Coast five, and Western region two, reflecting the widespread nature of the crisis.
Meanwhile, environmental scientists warn that the country may witness worse storms in the coming years due to ecological changes unfolding in the oceans. Weather experts say the ongoing heavy rains are a consequence of climate change.
Warming ocean
Climate scientist Clifford Omondi explains that a steady warming of the Indian Ocean is directly shaping the weather pattern being experienced in Kenya and the wider East African region. The conditions, he says, are tied to a powerful ocean-driven system known as the Indian Ocean Dipole (IOD), a climate phenomenon involving irregular sea surface temperature oscillations in the Indian Ocean. During a positive IOD phase, the western pole becomes warmer and the eastern pole cooler; during a negative phase, the pattern reverses.
A man scoops water from his flooded house in Salgaa trading centre in Nakuru on 22, 2026 following a heavy two-day down pour that has left scores of business community and resident counting huge losses.
Omondi notes that the influence of the IOD is intensifying due to rising global temperatures. “The warming acts like a moisture engine, pulling large amounts of water vapour into the atmosphere so that during a positive IOD phase, the moisture is released over East Africa, resulting in intense rainfall.”
Lamu County Director of Meteorological Services Ngao Leli says this trend brings increased climate extremes, including droughts in Indonesia and Australia, which are currently very cold and flooding in the East African region, which is currently warm. “The warmer ocean temperatures in the East Africa region mean lots of convective activity is taking place and clouds are formed, hence resulting in heavier, more destructive rainfall events like what is being witnessed at the moment,” says Leli.
Omondi notes the changes are closely tied to ocean temperature patterns, which have changed over time and will continue to shape the region’s weather.
“There is a more dangerous shift in the speed at which climatic conditions are changing. What has changed is not just climate but what we refer to as climatic predictability. The line between drought and flood is becoming thinner, and the swing between the two is also more abrupt,” he says.
According to Chris Ng’etich, a climate scientist at the Kenya Meteorological Department, the ongoing rains are largely convectional, driven by intense surface heating that forces warm, moisture‑laden air to rise rapidly, forming towering storm clouds and triggering thunderstorms.
Thunderstorms develop when three essential elements combine: moisture in the form of warm, humid air near the surface; atmospheric instability that allows this air to rise; and a lifting mechanism such as surface heating, terrain, or converging winds. This process leads to the typical lifecycle of a storm, beginning with the cumulus stage, intensifying into the mature stage marked by heavy rainfall, lightning, and thunder, and eventually weakening into the dissipating stage.
“With high atmospheric instability, abundant moisture, and elevated energy levels, conditions are primed for heavy downpours, a situation further intensified by warming oceans that are loading the atmosphere with more water vapour,” says Ng’etich.
High Convective Available Potential Energy (CAPE), abundant moisture from the Congo air mass and the Indian Ocean, together with atmospheric instability, have created perfect conditions for heavy downpours. Additionally, warmer ocean temperatures driven by climate change are increasing the amount of moisture in the atmosphere, leading to more intense and erratic rainfall events, sometimes referred to as “climate whiplash.”
Floodwaters mixed with garbage and raw sewage submerge a section of road in Pipeline Estate, Nairobi, on Sunday, March 22, 2026.
“Warmer oceans supply extra moisture, amplified by climate change, where the atmosphere holds more water vapour per 1°C warming, leading to more intense events,” says Ng’etich.
ITCZ and Congo air mass
Ng’etich further explains that aside from warming ocean temperatures, the main drivers include the position of the Inter‑Tropical Convergence Zone (ITCZ) and the Congo air mass as key contributors.
“The ITCZ’s position over Kenya, combined with the influx of moist Congo air, is a major driver of the widespread and intense rainfall currently being experienced,” he explains.
A man uses a rope to pull a container from flood water after heavy rains flooded a quarry within Kamulu area of Nairobi County, Kenya, March 6, 2026.
The ITCZ, a band where trade winds from the northern and southern hemispheres meet, is currently situated over the country, forcing moist air to rise and triggering widespread convection and thunderstorms.
Leli describes the ITCZ as a low‑pressure belt encircling the Earth near the Equator, where northeast and southeast trade winds converge. He stresses that currently, East Africa, where the Equator cuts directly through the region, passing through Uganda, Kenya, and southern Somalia, is witnessing very active movement of these northeasterly and southeasterly winds.
He further explains that northeasterly winds blow toward the southwest, while southeasterly winds blow toward the northwest, generally driven by tropical high‑pressure systems. Such winds play a crucial role in shaping climate and ocean currents, as well as transporting dust across oceans. Once these trade winds meet at the ITCZ, Leli notes, they often create intense rainfall and thunderstorms, similar to what is being witnessed in the East Africa region at the moment. “Once the two winds meet or converge at the equator region where we are, they create a low‑pressure belt known as the doldrums. Due to calm winds, this particular area of low pressure is characterised by intense heat, high humidity, and rising ocean vapours or water vapour, leading to cooling, condensation, and formation of clouds, resulting in heavy, daily rainfall at the end, shifting north and south seasonally,” says Leli.
Residents of Nyando and Nyakach in Kisumu County are counting losses following following heavy rains.
A key feature is the ITCZ’s meridional arm, which channels the Congo air mass—moist westerly and north‑westerly winds originating from the Congo Basin rainforest. Rich in water vapour due to intense evapotranspiration, this air mass moves eastward into Kenya and interacts with the country’s topography, leading to orographic uplift and heavy, localised rainfall, particularly across western Kenya, the Rift Valley, the central highlands, and Nairobi.
Physical landscape
Other contributing factors include the topography of the land and local effects, which work to enhance rainfall by lifting moist air over highlands and intensifying convection in areas influenced by lakes and urban heat. Kenya’s physical landscape and localised weather processes are said to significantly amplify the ongoing rainfall.
“Kenya’s diverse terrain plays a direct role in intensifying rainfall as elevated regions force moist air upward, leading to heavier precipitation, notes Ng’etich.
The country’s highlands and escarpments act as natural barriers, forcing moisture‑laden air to rise, cool, and condense, resulting in enhanced precipitation through orographic rainfall. This effect is particularly pronounced in areas such as the Aberdare Range, Mount Kenya, the central highlands, and parts of the Rift Valley, where uplift continues to trigger heavier and more sustained downpours.
At the same time, localised influences are further intensifying rainfall patterns. “Local factors, including lake breezes and urban heat, are further amplifying storm activity, making rainfall more intense and increasingly localised,” Ng’etich adds.
Kenya Red Cross officials conduct an assessment in Rachuonyo North, Homa Bay County, on March 8, 2026, following floods that have displaced families in the region
Lake Victoria contributes to increased afternoon and evening showers through land‑lake breeze interactions, while urban areas such as Nairobi are experiencing stronger downpours linked to the urban heat island effect, where built environments trap heat and enhance convection.
According to Ng’etich, atmospheric and oceanic systems remain highly dynamic, with constant shifts in pressure systems, wind circulation, and moisture transport pathways occurring over short periods. “The atmosphere is constantly evolving, and even small shifts in pressure systems or wind patterns can significantly alter where and how intensely rainfall occurs,” he explains.
These rapid changes influence how and where rainfall develops, often leading to sudden variations in both intensity and distribution across different regions. As a result, areas that may initially experience moderate rainfall can quickly transition to heavy downpours as these systems evolve and interact.
The rapid shifts in atmospheric and oceanic systems are making rainfall patterns increasingly unpredictable across Kenya. Sudden changes in wind direction, pressure systems, and moisture flows can turn light showers into heavy downpours within hours, leaving some regions caught off guard.
Forecasters track these changes closely; however, the speed and complexity of the systems mean rainfall can still vary widely over short distances.
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-By Kalume Kazungu, George Odiwuor and Kimani Mwangi
