Uneven rainfall expected across Kenya in October–December outlook

Kenya is expected to face an erratic short rains season this year, with the Meteorological Department warning of depressed rainfall, prolonged dry spells, and uneven distribution across different regions between October and December.

According to the October–December 2025 climate outlook released by the department, much of the Northeast, Southeastern lowlands, and coastal areas will receive below-average rainfall.

The South and Central Rift Valley, parts of the Lake Victoria Basin, and the Highlands East of the Rift Valley—including Nairobi, Kajiado, western Samburu and Marsabit—are projected to get near to below-average rainfall.

In contrast, the Highlands West of the Rift Valley and parts of Northwestern Kenya may experience near to above-average rainfall.

Charles Mugah from the department explained that the forecast is influenced by a developing negative Indian Ocean Dipole (IOD), expected to last from September through November before neutralizing in December.

“A negative IOD typically brings drier than normal conditions over East Africa, potentially suppressing rainfall during the short rains,” he said.

The World Meteorological Organisation has also indicated a 55 per cent chance of La Niña forming between September and November 2025, with the likelihood increasing to 60 per cent in October–December. The department said it will keep monitoring these developments.

Mugah emphasized that the short rains season is a crucial rainfall period for the central and eastern parts of the country, adding that the latest projections show a wide variation across different counties.

Kisii, Nyamira, Uasin Gishu, Kakamega and Bungoma are expected to receive near to slightly above-average rainfall with fair distribution and occasional storms.

Siaya, Kisumu, Homa Bay, Migori and southern Busia will likely record near to slightly below-average rainfall, except northern Busia which could receive near to above-average amounts.

Nakuru, Narok and parts of Baringo are forecast to receive poorly distributed near to slightly below-average rains.

Turkana and western Samburu may record near to slightly above-average rainfall, but with prolonged dry spells. Nairobi, Kiambu, Murang’a, Nyeri, Meru, Nyandarua, Embu and Tharaka Nithi are expected to receive near to below-average rainfall with poor distribution. Kitui, Makueni, Taita Taveta, parts of Machakos, Kajiado and Tana River are projected to face below-average rainfall, alongside Mandera, Wajir, Garissa, Isiolo and eastern Marsabit.

Coastal counties including Mombasa, Kilifi, Kwale and Lamu are also expected to experience below-average rains marked by breaks and occasional storms.

Alongside the seasonal forecast, the department issued its five-day weather advisory starting Friday, September 5, cautioning residents in several regions to prepare for moderate to heavy rains.

Counties in the Lake Victoria Basin, Highlands West and East of the Rift Valley, Northwest and Rift Valley—including Siaya, Kisumu, Homa Bay, Migori, Kisii, Nyamira, Trans Nzoia, Baringo, Uasin Gishu, Nandi, Nakuru, Narok, Kericho, Kakamega, Bungoma, Busia, West Pokot, Kericho, Bomet, Vihiga and Elgeyo Marakwet—will receive rainfall expected to intensify in the afternoons, often accompanied by thunderstorms.

In the Highlands East of the Rift Valley, covering Nyandarua, Laikipia, Nyeri, Kirinyaga, Murang’a, Kiambu, Meru, Embu, Tharaka Nithi and Nairobi, moderate rainfall is expected mainly in the afternoons after cloudy and sunny intervals in the mornings. The downpour in these areas is forecast to peak on Saturday, September 6.

While the western and highland regions brace for rains, the North-Eastern counties and Southeastern lowlands are expected to remain dry during the five-day period.

The department also issued a temperature advisory, warning of very cold nights in Nyandarua, Laikipia, Nyeri, Kirinyaga, Murang’a, Kiambu, Meru, Embu, Tharaka Nithi and Nairobi, where temperatures could fall by as much as 5°C.

Cold conditions are also expected in parts of Western Kenya, including Siaya, Kisumu, Kakamega, Kisii, Nyamira and Trans Nzoia.

In addition, strong southerly winds exceeding 12.86 metres per second are predicted over the Coast, the Southeastern lowlands, Northeastern and Northwestern regions.

The weather department urged residents in the affected counties to be cautious of flooding, thunderstorms, cold nights, and the potential risks posed by the strong winds.