NewzNAIROBI, Kenya, Aug 26 — Kenya is set for an enhanced October-December short rains season, with above-average rainfall expected across much of the country and prolonged wet spells likely to be accompanied by isolated storms, the Kenya Meteorological Service Authority (KMSA) has forecast. The outlook, presented during the 13th National Climate Outlook Forum on Wednesday, projects above-average rainfall across 80 per cent of the country, with rainfall expected to be fairly to well distributed over several areas. KMSA said the October–December 2026 “Short Rains” season “will be marked by prolonged wet spells and occasional isolated storms over several parts of the country.” The forecast comes as a strengthening El Niño event develops over the central-eastern equatorial Pacific, while the Indian Ocean Dipole (IOD) — a climate driver defined by the temperature difference between the western and eastern tropical Indian Ocean — remains neutral but is expected to move into its positive phase from September.
KMSA Director Edward Muriuki addresses the press/KMSA KMSA said the latest weekly Niño 3.4 index, centred on August 12, had reached +2.7°C, indicating that El Niño is strengthening towards a very strong event. The IOD stood at +0.17°C as of August 23, below the +0.4°C threshold required for a positive event. KMSA expects the index to surpass the threshold from September, although uncertainty remains over the timing and strength of the shift.
“The current IOD value is expected to increase in magnitude and surpass the threshold from September 2026 although some uncertainty remains regarding its timing and strength,” the authority said. When the rains will begin The onset of the rains will vary across the country, with some western counties expected to continue receiving rainfall from September while most other areas will see the short rains begin between October and November. Counties including Nandi, Kakamega, Vihiga, Bungoma, Siaya, Busia, Baringo, Nakuru, Trans Nzoia, Uasin Gishu, Elgeyo Marakwet, West Pokot, Kisii, Nyamira, Kericho, Bomet, Kisumu, Homa Bay, Migori and Narok are expected to continue receiving rainfall from September, with the season extending into January.
In Nyandarua, Laikipia, Nyeri, Kirinyaga, Murang’a, Kiambu, Meru, Embu, Tharaka-Nithi and Nairobi, onset is expected between the second and third weeks of October, with rains continuing into … NAIROBI, Kenya, Aug 26 – Kenya is headed for a wetter-than-usual October to December rainfall season, with the Kenya Meteorological Service Authority (KMSA) forecasting above-average rains across large parts of the country. The outlook released on Wednesday indicates that most counties are likely to receive above-normal rainfall during the 2026 short-rains season, with some areas expected to experience prolonged wet spells and isolated storms.
The forecast comes as the El Niño event in the equatorial Pacific continues to strengthen, while the Indian Ocean Dipole (IOD) is expected to move into its positive phase from September. KMSA said the strengthening El Niño and a potentially positive IOD could enhance rainfall during the season, although the timing and strength of the IOD remain uncertain. Among the areas expected to receive above-average rainfall are Nairobi, Kiambu, Murang’a, Nyeri, Nakuru, Kericho, Bomet, Kisii, Nyamira, Kisumu, Homa Bay, Migori, Siaya, Busia, Bungoma, Kakamega, Vihiga, Nandi, Uasin Gishu, Trans Nzoia, Elgeyo Marakwet, Baringo and Narok.
The forecast also places much of the Coast, eastern and northeastern regions in the above-average rainfall category, including Mombasa, Kilifi, Kwale, Lamu, Tana River, Garissa, Wajir, Mandera, Isiolo, Meru, Embu, Tharaka-Nithi, Kitui, Makueni and Machakos. Turkana and parts of West Pokot, Samburu and Marsabit are expected to record rainfall ranging from near average to above average. KMSA said rainfall distribution is expected to be fairly to well spread across much of the country, although Turkana and Samburu could experience poorer distribution.
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