For weeks, Kenyans in parts of the country have been looking at the skies and wondering when the October-December rains would settle in. The seasonal outlook had pointed toward wetter-than-normal conditions, yet the rain did not arrive everywhere at the same time.
Then meteorologists began watching a tropical storm developing over the southwest Indian Ocean.
The storm, named Agueda, became one of the factors Kenya's weather authorities were monitoring as they tried to explain why the expected rains had been delayed in some areas.
The Kenya Meteorological Services Authority said the storm's eventual path could either help bring rainfall toward Kenya or contribute to continued dry conditions, depending on its trajectory.
Agueda was only one piece of the puzzle. But its appearance offered a glimpse into something that can be easy to forget when looking at a weather forecast: the rain falling over Kenya can depend on atmospheric systems developing far beyond the country's borders.
Kenya was expecting rain. So why was it delayed?
Kenya's October-November-December season is one of the country's important rainfall periods, particularly for agriculture and water resources. The regional forecast issued by the IGAD Climate Prediction and Applications Centre, or ICPAC, indicated a greater likelihood of wetter-than-normal conditions across much of the Greater Horn of Africa, including large parts of Kenya.
But a seasonal forecast does not mean every county will receive rain on the same day.
ICPAC's outlook itself anticipated differences in rainfall onset, including delayed onset in some western areas, while the Kenya Meteorological Department's own forecasts are designed to provide more localized information as the season develops.
That distinction became important in October.
Some parts of Kenya had already received substantial rainfall, while other areas were still waiting for conditions that would meet the official definition of rainfall onset.
Hannah Kimani, Director of Public Weather Services at the Kenya Meteorological Services Authority, told Nation that rainfall onset had already occurred in parts of the country, including some coastal and western areas, while other regions were expected to experience onset later.
The system that helps bring Kenya its rain
Part of the explanation lies in a broad atmospheric feature called the Intertropical Convergence Zone, or ITCZ.
The ITCZ is a belt of relatively low pressure around the tropics where winds from the Northern and Southern Hemispheres meet. Its seasonal movement influences where moisture and rainfall are concentrated across much of the tropics.
For Kenya's October-December season, the southward movement of the ITCZ is particularly important.
Kimani explained that the system had begun moving southward and had contributed to rainfall onset in some parts of Kenya. But a series of low-pressure systems over the northern Indian Ocean temporarily disrupted its continued movement, leaving some areas drier than expected.
That is why the story cannot simply be reduced to, "the rains were late."
The atmosphere was moving, but not necessarily in the way or at the pace that would bring sustained rainfall to every part of the country.
Then meteorologists started watching Agueda
This was where the tropical storm entered the picture.
As Agueda formed over the southwest Indian Ocean, Kenya's weather authorities began monitoring its movement because its trajectory could influence the atmospheric conditions affecting rainfall over East Africa.
Kimani explained that the storm's impact would depend heavily on where it travelled.
“If it moves north of Madagascar and westward, it will bring us rainfall if other factors are in agreement,” she told Nation. “If it moves South of Madagascar and westwards, it will worsen the dry weather conditions.”
That is an important distinction.
A tropical storm does not simply carry rain toward Kenya like a moving cloud. Its position and movement can influence atmospheric circulation and the transport of moisture, while other weather systems determine how that moisture eventually behaves.
For meteorologists, therefore, the storm was something to monitor, not a guaranteed source of rain.
El Niño adds another layer to the story
There is another major climate driver behind this year's rainfall outlook: El Niño.
ICPAC's August outlook said El Niño had developed and was expected to strengthen during the remainder of 2026, while a positive Indian Ocean Dipole was also expected to contribute to wetter-than-normal conditions across much of the Greater Horn of Africa.
The regional forecast gave a particularly high probability of enhanced rainfall over northeastern Kenya. But El Niño does not mean rain everywhere.
The World Meteorological Organization has stressed that El Niño can shift rainfall and temperature patterns differently across regions. Its latest October update said the event was strengthening and could become exceptionally strong, with tropical Pacific sea-surface temperatures forecast to reach about 3.8°C above average during November 2026 to January 2027.
WMO Secretary-General Celeste Saulo described the projected conditions as being "off the monitoring charts" used over the past four decades, while stressing that seasonal outlooks are not predictions of individual weather events.
For Kenya, that distinction matters.
A large-scale climate pattern can increase the likelihood of wetter conditions while shorter-term atmospheric systems still determine where and when individual rainfall events occur.
What Happens Next
Agueda was never the whole explanation for Kenya's delayed rains.
It was one piece of a much larger atmospheric puzzle involving the ITCZ, Indian Ocean conditions, El Niño and the constantly changing movement of moisture through the region.
That is what makes Kenya's rainfall story more complicated than a forecast headline.
The seasonal outlook can point toward a wetter-than-normal season while individual weeks remain dry. A tropical storm can influence atmospheric conditions without becoming the direct "cause" of a country's weather. And rainfall can arrive in one county while farmers elsewhere continue looking toward the same sky and waiting.
