El Niño in Nandi County: flood risk and farm advice

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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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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.

Reports from people (0 reports in the last 60 days)Rivers, drains and road crossings

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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 Nandi: questions and answers

Will El Niño cause floods in Nandi this season?

Nandi has low flood risk this season compared with other counties (40th of 47 for people and buildings in the way). About 18 km² is expected to flood in October–November 2026: between 13 and 29 km², depending on how the season ends. About 1 km² of it is farmland. That is more than in a typical El Niño short rains here (about 1.5 times). About 1,500 people live on land likely to flood, among 0 hectares of buildings and roads. These estimates use Kenya Met’s rain forecast for 5 Oct to 15 Nov 2026.

Which parts of Nandi are most likely to flood?

The most flooding this season is expected in Chemelil/Chemase, Kaptel/Kamoiywo and Songhor/Soba wards. The most flood-prone farmland is in Songhor/Soba and Chemelil/Chemase.

What should farmers in Nandi plant in the Oct–Dec 2026 short rains?

Kenya Met expects about 1.6 times the usual rain here from 5 Oct to 15 Nov. Maize: in past El Niño short rains, maize here did better than usual in 0 of 2 seasons and worse in none. Plant early with the first good rains. 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 Nandi protect crops from El Niño floods?

Some low-lying farmland may flood; avoid planting right next to rivers and swamps. Steep slopes in Tindiret, Terik and Kapchorua 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 Nandi flooded in past El Niño years?

About 40 km² of Nandi was at high flood risk in 3 or more of the 11 El Niño seasons since 1991. About 5,700 people live on that land, the 31st most of Kenya’s 47 counties. Disaster records, news and relief reports list 11 floods and 3 landslides in Nandi between 2009 and 2026. The most severe El Niño event recorded here: Nandi (2015-12).

Is Nandi at risk of landslides?

53% of Nandi is steep, landslide-prone ground, most of it in Tindiret, Terik and Kapchorua. Heavy El Niño rain fell on these slopes in 9 of 11 El Niño seasons.

More for Nandi

Daily rain forecast for Nandi, ward by ward, from Kenya Met.

Seen flooding, a landslide or a road cut off? Report it so others can see it on the map.