Kenya Short Rains 2026: When El Niño Rains Start, by Region

By the 254.ke Newsroom.

Kenya’s October-December short rains are expected to begin in the second and third weeks of October in most regions, with about 80 per cent of the country forecast to get more rain than normal, according to the Kenya Meteorological Service Authority (KMSA). The outlook was released in August; as of September 29, 2026, forecasters say the exact start date still depends on how a strong El Niño interacts with the Indian Ocean Dipole.

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Here is what is known about timing by region, who is most at risk, and what government and health agencies are asking people to do before the first heavy downpour.

When will the 2026 short rains start in Kenya?

The government’s latest preparedness briefing, reported by The Star on September 28, gives onset windows by region. Western Kenya, the Rift Valley and the Lake Victoria Basin are expected to see rainfall from September through January, so residents there are already in the wet period.

Region	Expected onset (2026)
Western Kenya, Rift Valley, Lake Victoria Basin	September to January
Nairobi, Central Kenya, Eastern highlands	Second to third week of October
Coast and north-eastern counties	Second to third week of October
South-eastern lowlands	Third to fourth week of October

KMSA Director Edward Muriuki said in August that people should “expect enhanced rainfall in most parts of Kenya” over the season, with prolonged wet spells and occasional isolated storms. Coastal areas are also expected to be warmer than average.

Why are forecasters cautious about the exact start date?

The Kenya Meteorological Department (KMD) put the chance of a very strong El Niño this year at 81 per cent, and the chance that it lasts into early 2027 at 97 per cent. But KMD’s Hannah Kimani has stressed that El Niño strength alone does not decide how much rain Kenya gets. The Indian Ocean Dipole can either amplify or dampen its effect.

A September 10 report by Streamlinefeed quoted weather analyst Maithya wa Vilivū saying medium-range models were sending mixed signals, with predictability of roughly 50 to 70 per cent in most regions. Narok’s county meteorological director, Stanley Kinyua, said the season’s outcome depends mainly on the dipole. In short, the direction of the forecast is clear (wetter than normal), while the day the rains arrive in your town is not.

Which counties are most exposed?

KMSA’s outlook lists above-average rainfall for Nairobi, Mombasa, Kilifi, Nakuru, Kiambu, Machakos, Makueni, Garissa, Mandera, Wajir, Kisumu, Kakamega, Kisii, Nyeri and Nyandarua. Turkana and parts of West Pokot, Samburu and Marsabit are expected to see near-to-above-average rain, with uneven distribution.

The National Disaster Operations Centre (NDOC) has gone further on risk. In an August briefing, it estimated that 1.5 million people could be affected and 500,000 displaced in a worst-case scenario. It named Mandera, Wajir, Garissa, Tana River, coastal counties, Elgeyo-Marakwet, Baringo, Murang’a, Kiambu, Kisumu and Busia among the areas of concern. For a fuller county-by-county look, see our earlier report on Kenya’s 18 high-risk flood counties.

What are the government and health agencies doing?

NDOC Director Col (Rtd) David Samoei has told counties to identify safe shelters for families who may be displaced, and has asked that schools not be used. Sites should be away from flood-prone ground and have water, sanitation, electricity and road access. Other measures reported by The Star include:

early warning systems and evacuation planning, with flood and landslide hotspots identified;
mapping of vulnerable groups, including the elderly, people with disabilities, children and pregnant women;
checks on roads, bridges, culverts and dams, and clearing of urban drains;
stronger health surveillance and disease monitoring;
agricultural advice on drainage and crop protection.

The World Health Organization’s Kenya office said on September 8 that it is supporting the Ministry of Health and the Kenya National Public Health Institute on a health-sector El Niño contingency plan. WHO warned that flooding can contaminate water and raise the risk of cholera, typhoid, dysentery, hepatitis A and other diarrhoeal diseases. It noted that the March to May 2026 floods affected 27 counties, killed 122 people and affected 42,259 others.

In Nairobi, the county government has already moved to waive building repair permits ahead of El Niño.

What should households do before the rains?

Know your risk. Check whether you live near a river, a drainage channel or a steep slope, and plan a route to higher ground.
Clear gutters and drains around your home and repair leaking roofs now, not during the first storm.
Protect drinking water. Boil or treat water after floods, and keep latrines and water sources separate.
Follow official updates. Weather advisories come from KMD, and the emergency hotline reported by The Star is 0800 721 571.
Farmers: prepare drainage channels and follow county agricultural advice on planting dates, since forecasts remain uncertain on onset.

Frequently asked questions

Are the short rains 2026 expected to be heavier than normal?

Yes. KMSA forecasts above-average rainfall over about 80 per cent of Kenya between October and December 2026.

When do the short rains start in Nairobi?

Nairobi and Central Kenya are expected to see onset in the second to third week of October, according to the government’s latest briefing.

Which parts of Kenya are drier than normal?

KMD has said the south-eastern lowlands and the north-east could see below-average rainfall in some outlooks, and an earlier July outlook warned that western cereal-growing counties could see depressed rainfall before October. Check the latest KMD county forecast for your area.

Is El Niño confirmed for 2026?

KMD puts the probability of a very strong El Niño at 81 per cent, and regional forecasters at the Greater Horn of Africa Climate Outlook Forum have given a 99 per cent chance that El Niño occurs, according to NDOC.

Where can I get official weather updates?

From the Kenya Meteorological Department at meteo.go.ke, which publishes weekly and seasonal outlooks.

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