El Niño Raises Heavy Rain and Flood Risks Across Horn of Africa

The wetter outlook is closely connected to the developing El Niño event, which is expected to strengthen during the rest of 2026, while a positive phase of the Indian Ocean Dipole is also expected to develop.

The Greater Horn of Africa is heading into the final months of 2026 with a strong likelihood of wetter and warmer conditions as El Niño intensifies, bringing the prospect of improved water and pasture supplies alongside serious concerns about flooding, crop losses, disease and infrastructure damage. A new seasonal outlook from the IGAD Climate Prediction and Applications Centre (ICPAC), developed with National Meteorological and Hydrological Services across the region, points to above-normal rainfall during the crucial October-to-December season.

These three months carry enormous importance for communities across the equatorial and southern Greater Horn of Africa because they can provide as much as 70 percent of annual rainfall in parts of Ethiopia, Kenya and Somalia. Parts of Rwanda, Burundi, Tanzania and Uganda receive up to 40 percent of their yearly rainfall during the same period, making the performance and timing of the season closely tied to agriculture, livestock, food security and water availability.

El Niño and Indian Ocean Conditions Drive Wetter Forecast

The wetter outlook is closely connected to the developing El Niño event, which is expected to strengthen during the rest of 2026, while a positive phase of the Indian Ocean Dipole is also expected to develop. This combination of climate conditions is commonly associated with enhanced rainfall across parts of East Africa during the October-to-December rainy season.

ICPAC's regional forecast shows particularly strong signals in several areas, including a 90 percent chance of enhanced rainfall across southern Ethiopia, central and southern Somalia and northeastern Kenya. Seasonal rainfall could exceed 400 millimetres in parts of central and southern Somalia, central Kenya, the Lake Victoria Basin, Burundi, western Rwanda and western Tanzania.

The rains are also expected to begin early or around their normal starting dates across much of the eastern and southern region, including Somalia, central and eastern Kenya, southern Ethiopia and most of Tanzania. The combination of an early or normal onset and heavier seasonal rainfall could provide valuable water for farming and livestock, while communities in flood-prone areas may face a very different set of challenges.

More Rain Could Help Livestock but Increase Flood Threats

Above-average rainfall can restore pasture, refill water sources and improve conditions for livestock-dependent households after periods of dryness. The Food Security and Nutrition Working Group has warned that excessive rainfall can also trigger destructive flooding, putting lives, crops, roads, homes and other essential infrastructure at risk.

Heavy rain and standing floodwater can increase exposure to water-borne and vector-borne diseases, while damaged roads and flooded communities can make it harder for people to reach healthcare and nutrition services. These risks make early warnings especially important for governments and humanitarian organizations preparing for a season that could bring both agricultural benefits and significant disruption.

Temperatures are expected to remain another concern, with warmer-than-average conditions forecast across most of the Greater Horn of Africa. The strongest probabilities of unusual warmth are concentrated in eastern parts of the region, particularly eastern Kenya, Ethiopia, Eritrea, Djibouti and much of Somalia.

Past El Niño Years Offer Lessons for 2026 Preparedness

Climate specialists have identified 1997 and 2023 as useful analogue years because both experienced wetter-than-normal conditions across much of the region during the October-to-December season. Each El Niño develops differently, meaning past events cannot provide an exact picture of what communities will experience in 2026, but they can help authorities understand possible impacts and prepare for periods of intense rainfall.

The new outlook was issued during the Greater Horn of Africa Climate Outlook Forum in Kigali, Rwanda, on August 17-18, bringing together representatives from Burundi, Djibouti, Ethiopia, Kenya, Rwanda, Somalia, South Sudan, Sudan, Tanzania and Uganda. Agriculture, food security, livestock, health, water resources, disaster management and humanitarian organizations were also represented, reflecting how widely seasonal climate conditions can affect daily life and economic activity.

The World Meteorological Organization is scheduled to issue its next El Niño Update on September 3, while national meteorological agencies will provide more detailed country-level forecasts and advisories. These updates will be important as governments, farmers, humanitarian groups and communities prepare for potentially intense rainfall and unusually warm conditions during the closing months of 2026.