NAIROBI, Kenya Oct 5 – Heavy rains are expected in several parts of Kenya during the October-December rainfall season, raising the prospect of improved water and pasture supplies but also flooding, waterlogging and disruption of farming activities.The Kenya Meteorological Service said the season had officially begun, with rainfall already recorded in parts of western Kenya, the Rift Valley and the Coast. Other parts of the country are expected to receive the rains at different times through October.Some of the areas likely to receive the heaviest rainfall are the Coast and northeastern regions, including Kwale, Mombasa, Kilifi, Lamu and Mandera. Parts of Taita Taveta, Tana River, Garissa and Wajir are also expected to record substantial rainfall.The forecast extends to several counties in central Kenya and the southeast, where above-average rainfall is expected in Makueni, Kajiado, Machakos, Nairobi, Kiambu, Murang’a, Kirinyaga, Embu, Tharaka Nithi, Meru, Isiolo, Nyandarua and Nyeri.Parts of Marsabit, Laikipia, Nakuru and Narok are also expected to receive above-average rainfall.Acting head of the Kenya Meteorological Service Authority Edward Muriuki said rainfall had already started in 24 counties, although the onset would not be uniform across the country.Western and Rift Valley counties that have recorded the start of the season include Nandi, Kakamega, Vihiga, Bungoma, Siaya, Busia, Baringo, Nakuru, Trans Nzoia, Uasin Gishu, Elgeyo Marakwet, West Pokot, Kisii, Nyamira, Kericho, Bomet and Narok.Kisumu, Homa Bay and Migori have also recorded rainfall, alongside Mombasa, Kwale, Lamu and Kilifi at the Coast and the Tana Delta.The onset is expected to move into other regions during the coming weeks.Marsabit, Mandera, Wajir, Garissa and Isiolo are expected to receive the rains during the first or second week of October.In central Kenya and Ukambani, the onset is expected in the second or third week of the month. The areas include Nairobi, Kiambu, Murang’a, Kirinyaga, Nyeri, Nyandarua, Laikipia, Embu, Meru, Tharaka Nithi, Machakos, Kitui and Makueni.Kajiado, Taita Taveta and inland areas of Tana River are also expected to receive the rains during this period.Turkana and Samburu will be among the last counties to record the onset, with rainfall expected in the third or fourth week of October.Muriuki called on farmers to avoid relying on the national outlook alone, saying local variations in rainfall would require them to consult forecasts issued for their respective counties.“County-specific weekly and monthly forecasts are available from the offices of respective county directors of Meteorological Services,” he said.The expected rains could provide relief to farmers and livestock keepers by improving soil moisture, replenishing water sources and regenerating pasture. They are also expected to support land preparation and planting in areas where rainfall has been inadequate.But the Met warned that excessive rainfall could have adverse effects, including waterlogged farms, increased crop diseases and difficulties moving agricultural produce from farms to markets.Heavy rainfall could also disrupt normal activities in areas prone to flooding.The outlook comes amid changes in major climate systems influencing rainfall across the region. The October-December season is affected by both El Niño and the Indian Ocean Dipole, a climate phenomenon driven by differences in sea surface temperatures between the western and eastern tropical Indian Ocean.The World Meteorological Organisation expects a positive Indian Ocean Dipole to develop during September-November, while El Niño conditions strengthen.However, Muriuki cautioned against attributing the season’s rainfall to El Niño alone.“Rainfall is influenced by several climate systems, including El Niño and the Indian Ocean Dipole,” he said.Temperatures are also expected to remain above average in most parts of the country during the season.The rainfall is expected to persist into January in many parts of central, western and eastern Kenya. However, the season is expected to wind down earlier in Marsabit, Mandera, Wajir, Garissa and Isiolo, where rains could end in the first or second week of December.Despite the generally wetter forecast, Turkana and Samburu are expected to receive poor to fair rainfall during the season.