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Chance that each place floods in October–November 2026: the average of possible ways the season could end, driven by Kenya Met’s forecast for the first six weeks.
El Niño in Trans Nzoia County: flood risk and farm advice
Trans Nzoia has low flood risk this season, moderate flood risk in past El Niño years and moderate landslide risk. About 9 km² of Trans Nzoia is expected to flood in October–November 2026.
Explore by county and ward
Choose a county to see what to expect this season and what happened in past El Niño years, then a ward for local numbers. Tap the map or pick from the lists.
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How far to trust it, and how it was made
How much can you trust this?
- Good at where. The map finds the places that flood: two in three recorded floods were in the most flood-prone fifth of Kenya.
- Counties rank by who is in the way. Flood ranks average two measures: the people living on land likely to flood, and the buildings and roads there. Ranking by flooded area alone mostly ranked county size, putting small, crowded Mombasa 45th of 47.
- Rougher on how much. Flooded areas are estimates, often larger than what satellites saw, so compare places rather than reading exact numbers.
- Sudden town floods are harder. Floods that drain within hours, as in Nairobi’s streets, are under-represented.
- The season outlook is a planning aid. It uses Kenya Met’s pilot forecast for the first six weeks and past El Niño Novembers after that.
- Landslides are mapped by slope. Most recorded landslides were too small for satellites to confirm, so treat the map as where to look, not a prediction.
How this was made
Floods. We trained a computer model on satellite flood maps from three recent El Niño seasons (2015–16, 2018–19 and 2023–24), rainfall records back to 1991, and maps of land, rivers and soils, then checked it against floods recorded in national and international disaster databases, relief agency updates and news reports.
Towns. Satellites cannot see floods between buildings, so town wards are rated from where floods were reported in similar towns: flat, low-lying ground, heavy bursts of rain and built-up cover.
Crops. County harvest records from 1991 to 2024 were compared across El Niño, La Niña and ordinary seasons. The advice names only crops with a clear El Niño pattern in counties with similar short-rains rainfall, and adds this season’s flood and landslide outlook.
Key studies behind the methods
- El Niño and East African rain: Indeje, Semazzi & Ogallo 2000 (doi); Black, Slingo & Sperber 2003 (doi)
- Satellite flood maps: Salamon et al. 2021, global satellite flood monitoring (doi)
- Gradient boosting and random forests: Friedman 2001 (doi); Breiman 2001 (doi)
- Testing on places the model never saw: Roberts et al. 2017 (doi)
- Learning from reports that follow people: Phillips et al. 2009 (doi); Warton, Renner & Ramp 2013 (doi)
- Cities, towns and countryside: Dijkstra et al. 2021, Degree of Urbanisation (doi)
- Built-up cover and floods: Shuster et al. 2005 (doi); Fekete 2022, Nairobi and Nyeri (doi); Tom et al. 2022, Nairobi review (doi)
- El Niño and crop yields: Iizumi et al. 2014 (doi); Cao et al. 2023 (doi)
- Using El Niño forecasts in farming: Adams et al. 2003 (doi); Hansen 2002 (doi)
- Landslides in El Niño years: Ngecu & Mathu 1999 (doi)
- Rift Valley fever after El Niño floods: Linthicum et al. 1999 (doi); Nguku et al. 2010 (doi)
- Aflatoxin in wet harvests: Lewis et al. 2005 (doi)
What the data covers
- Rainfall: daily satellite rainfall estimates, 1991–2026
- Flood maps: radar satellite flood maps of the 2015–16, 2018–19 and 2023–24 El Niño seasons
- This season’s forecast: Kenya Met’s pilot forecast for the Oct–Dec 2026 short rains
- Land, rivers and soils: elevation, river network, soil and land-cover maps
- Harvests: county crop records (maize by season, 1991–2024; 30 other crops by year, 1991–2022)
- Town traits: built-up surface, population, settlement type, roads, rivers, soils and soil moisture
- Recorded floods and landslides: national and international disaster databases, relief agency updates, Kenyan news reports and a global landslide catalogue
El Niño in Trans Nzoia: questions and answers
Will El Niño cause floods in Trans Nzoia this season?
Trans Nzoia has low flood risk this season compared with other counties (29th of 47 for people and buildings in the way). About 9 km² is expected to flood in October–November 2026: between 7 and 19 km², depending on how the season ends. About 2 km² of it is farmland. That is more than in a typical El Niño short rains here (about 1.4 times). About 1,900 people live on land likely to flood, among 10 hectares of buildings and roads. These estimates use Kenya Met’s rain forecast for 5 Oct to 15 Nov 2026.
Which parts of Trans Nzoia are most likely to flood?
The most flooding this season is expected in Endebess, Motosiet and Waitaluk wards. The most flood-prone farmland is in Chepchoina, Kapomboi and Matumbei.
What should farmers in Trans Nzoia plant in the Oct–Dec 2026 short rains?
Kenya Met expects about 1.4 times the usual rain here from 5 Oct to 15 Nov. Maize: too few past El Niño seasons on record here to say; most of Kenya does well. Good bets: cowpeas and kale (sukuma wiki). In counties like this one, these crops have usually done better in El Niño years. Take care with: cassava — plant on ridges or mounds so roots do not rot.
How can farmers in Trans Nzoia protect crops from El Niño floods?
About 2 km² of farmland may flood this season, most of it in Chepchoina, Kapomboi and Matumbei. Hold off planting low-lying riverside fields until the high water passes, or plant on raised beds; clear drains. Steep slopes in Matumbei, Chepsiro/Kiptoror and Saboti can slide in heavy rain: keep terraces and grass strips, do not dig into slopes, and move away if cracks open. Harvest promptly and dry grain well, off the ground, so it does not grow mould (aflatoxin).
Has Trans Nzoia flooded in past El Niño years?
About 21 km² of Trans Nzoia was at high flood risk in 3 or more of the 11 El Niño seasons since 1991. About 21,000 people live on that land, the 14th most of Kenya’s 47 counties. Disaster records, news and relief reports list 27 floods and 1 landslide in Trans Nzoia between 2008 and 2026. The most severe El Niño event recorded here: Trans Nzoia (2015-12).
Is Trans Nzoia at risk of landslides?
31% of Trans Nzoia is steep, landslide-prone ground, most of it in Matumbei, Chepsiro/Kiptoror and Saboti. Heavy El Niño rain fell on these slopes in 5 of 11 El Niño seasons.
More for Trans Nzoia
El Niño risk in other counties
- BaringoModerate risk
- BometLow risk
- BungomaLow risk
- BusiaLow risk
- Elgeyo-MarakwetLow risk
- EmbuModerate risk
- GarissaVery high risk
- Homa BayLow risk
- IsioloLow risk
- KajiadoModerate risk
- KakamegaModerate risk
- KerichoLow risk
- KiambuModerate risk
- KilifiVery high risk
- KirinyagaModerate risk
- KisiiModerate risk
- KisumuHigh risk
- KituiLow risk
- KwaleHigh risk
- LaikipiaModerate risk
- LamuLow risk
- MachakosLow risk
- MakueniLow risk
- ManderaHigh risk
- MarsabitLow risk
- MeruHigh risk
- MigoriModerate risk
- MombasaHigh risk
- Murang'aLow risk
- NairobiVery high risk
- NakuruVery high risk
- NandiLow risk
- NarokModerate risk
- NyamiraLow risk
- NyandaruaLow risk
- NyeriModerate risk
- SamburuLow risk
- SiayaLow risk
- Taita TavetaLow risk
- Tana RiverHigh risk
- Tharaka-NithiLow risk
- Trans NzoiaLow risk
- TurkanaVery high risk
- Uasin GishuHigh risk
- VihigaLow risk
- WajirModerate risk
- West PokotLow risk