Greater Horn of Africa Faces High-Risk Rainfall Season as El Niño Takes Hold

The Greater Horn of Africa is likely to experience wetter- and warmer-than-normal conditions during the October-to-December 2026 season as El Niño strengthens and a positive Indian Ocean Dipole develops. The outlook could improve water, pasture and agricultural conditions in some areas, but it also raises the prospect of flooding, crop damage, disease outbreaks and infrastructure disruption across a region where these three months provide a large share of annual rainfall.

More rain could bring desperately needed water and pasture while simultaneously deepening the risk of floods, crop damage, disease and infrastructure disruption in the Greater Horn of Africa. Forecasts from the IGAD Climate Prediction and Applications Centre (ICPAC) for the October-to-December season suggest wetter-than-normal conditions across large parts of the region as El Niño strengthens and a positive Indian Ocean Dipole develops. For governments and communities, the challenge will be converting an apparently favourable rainfall outlook into gains without allowing extreme weather to turn those gains into another humanitarian setback.

The stakes are especially high because these three months are central to the region's agricultural and water calendar. Parts of Ethiopia, Kenya and Somalia can receive as much as 70 percent of their annual rainfall during this period, while parts of Rwanda, Burundi, Tanzania and Uganda receive up to 40 percent. Even small changes in the timing or intensity of rainfall can quickly influence crop production, livestock conditions, water supplies and food security.

More Rain Does Not Automatically Mean Greater Security

The strongest rainfall signals are concentrated across some of the region's most climate-sensitive areas. Southern Ethiopia, central and southern Somalia and northeastern Kenya have a 90 percent chance of enhanced rainfall, while seasonal totals could exceed 400 millimetres in parts of Somalia, central Kenya, the Lake Victoria Basin, Burundi, western Rwanda and western Tanzania. Rains are also expected to begin early or around their normal onset across much of the eastern and southern Greater Horn.

On paper, those conditions offer significant advantages. Stronger rainfall can restore grazing areas, replenish surface water and ease pressure on pastoral households that depend heavily on pasture and livestock. Farmers may also benefit when rains arrive at the right stage of planting and crop development, particularly in areas where the October-to-December season determines a large part of annual agricultural performance.

However, rainfall benefits depend heavily on distribution, duration and intensity. A season that produces ample water over several months may support crops and livestock, while the same seasonal total delivered through repeated downpours can destroy fields, wash away roads and isolate communities.

El Niño and the Indian Ocean Are Amplifying the Signal

Two major climate drivers are reinforcing expectations of a wetter season. El Niño is expected to intensify through the remainder of 2026, while a positive Indian Ocean Dipole is also projected to develop. Together, these conditions are commonly associated with enhanced rainfall across parts of East Africa during the October-to-December period.

This combination increases confidence that the coming season may differ materially from an average year. Yet seasonal forecasting remains probabilistic rather than deterministic, meaning a strong regional signal cannot reveal exactly where flooding will occur or which districts will receive the heaviest rainfall. National and local forecasts will therefore become increasingly important as the season approaches.

The comparison with 1997 and 2023 adds another layer to the risk assessment. Both years experienced wetter-than-normal conditions across much of the region and are being used as analogues for preparedness, but they should not be treated as templates for 2026. Each El Niño develops differently, and local impacts depend on the interaction between large-scale climate patterns and conditions on the ground.

Flood Risk Could Cascade Far Beyond Farms

The most immediate danger from excessive rainfall is flooding, but the consequences can spread rapidly into health, transport and humanitarian systems. Heavy rain can damage homes, crops and roads while cutting communities off from markets, clinics and nutrition services. Standing water can also increase exposure to water-borne and vector-borne diseases, turning a weather shock into a broader public-health challenge.

Infrastructure resilience may become one of the defining issues of the season. Roads and bridges that fail under flood pressure do more than disrupt transport; they can delay food deliveries, emergency assistance and access to medical care. In rural areas, those disruptions can amplify losses even after floodwaters begin to recede.

The warmer-than-average temperature forecast adds further complexity. Most of the Greater Horn is expected to experience unusual warmth, with the strongest probabilities in eastern Kenya, Ethiopia, Eritrea, Djibouti and much of Somalia. The combination of heavier rainfall and persistent warmth means authorities may have to manage overlapping environmental pressures rather than treating flooding, agriculture and public health as separate problems.

This is why seasonal preparedness cannot stop at issuing weather warnings. Governments and humanitarian agencies will need to consider whether communities understand those warnings, whether evacuation and response systems can function when roads are damaged, and whether health and nutrition services remain accessible during prolonged disruption. The effectiveness of preparedness will ultimately be measured not by forecast accuracy alone, but by whether early information changes decisions before the most damaging conditions arrive.

The Real Test Will Be How Early Warnings Turn Into Action

The coming months will reveal whether regional climate intelligence can translate into practical risk reduction. The Greater Horn of Africa Climate Outlook Forum has already brought together governments, meteorological services, agriculture specialists, food-security agencies, health experts, water authorities and disaster-management organizations. The breadth reflects the reality that a strong rainy season can affect almost every layer of economic and social activity at once.

The next phase will depend increasingly on country-level detail. National meteorological agencies are expected to issue more localized forecasts and advisories, while the World Meteorological Organization is scheduled to provide its next El Niño update on September 3. Those assessments should sharpen understanding of where rainfall risks are intensifying and where early intervention may be most urgent.

For farmers, pastoralists and communities in flood-prone areas, the distinction between a beneficial wet season and a destructive one may come down to timing and preparedness. Early planting decisions, livestock movement, drainage management, infrastructure protection and access to warnings could all influence how much value the additional rainfall ultimately delivers. The same weather pattern may therefore produce recovery in one area and severe disruption in another.