Mixed Rainfall Impacts and Growing Concerns for the Eastern Horn of Africa

• Intense rainfall occurring within short periods across Ethiopia, South Sudan, and Sudan has produced both beneficial and destructive impacts. While replenishing soil moisture and improving water availability, the heavy downpours have also triggered severe flooding, landslides, and hailstorms that have devastated already mature crops, destroyed property and infrastructure, displaced large populations, and claimed lives.
• Across unimodal regions of Kenya and Uganda, the March–November rainfall season performed above average, supporting favorable crop development leading to above- average production prospects.
• There are concerns across the eastern horn following a below-average forecast for the October through December (OND) 2025 rainfall season associated with a present negative Indian ocean dipole and forecast La Niña.

March – November

Context: Between March and November, the following are the areas and names of the rainy seasons underway in parts of East Africa: Gu rains in Somalia; long rains in unimodal Uganda, Kenya, Burundi, and Rwanda; belg rains (mid-February to May) in Ethiopia, as well as the diraac/sugum rains in the northern pastoral area and gu/genna rains in the southern and southeastern pastoral areas of Ethiopia; and the first season rains in the bimodal zones of southwestern Ethiopia, southwestern South Sudan, and northern Uganda. This also marks the start of the October–December season

Harvesting is underway across the unimodal cropping zones in North-Rift, Kenya and Karamoja region, Uganda, this is likely to continue until November. The production prospects are expected to be above average following a wetter-than-average rainfall season that started on time and was well distributed both in space and time (Figure 2).

The Ethiopian Belg season from March to May 2025 exhibited mixed results across different regions. In the Southern region, the performance was classified as normal to above normal, with average yields for Belg crops being harvested. Conversely, areas such as eastern Oromia, eastern Amhara, Southern Tigray, and the northern pastoral zones (most of Afar and Northern Somali regions) experienced significantly below-average rainfall. This deficit in precipitation adversely affected both Belg crop cultivation and livestock body conditions in the aforementioned areas, highlighting regional disparities in agricultural performance during this season. 

June – September

Context: Between June and September, the following are the areas and names of the rainy seasons underway in parts of East Africa: Kiremt rains (June to September) in Western, Central, Northern, and Eastern Ethiopia; main rainy season (June to September) in the unimodal zones of South Sudan and Sudan; long rains in unimodal Uganda and Kenya; Karan/Karma rains (July to September) in northern pastoral areas of Ethiopia, Sitti and Fafan zones of Somali (Ethiopia) and the northern sector of Somalia; and second rains (July to November) in South Sudan bimodal zone.

The June–September rains were initially characterized by a delayed onset of up to two months across the Sudans, parts of Ethiopia, and Somalia. The Xagaa rains in Somalia along the southern coastal areas, as well as the adjacent agropastoral and riverine zones of the Shabelle and Juba regions in southern Somalia, were largely poor. This resulted in very low crop production, limited access to river water for irrigation, and depletion of pasture and water resources. From mid-July through September, intense rainfall has been experienced in central Ethiopia, western and eastern Sudan and most parts of South Sudan leading to flooding (Figure 3). In Ethiopia, the Kiremt rainfall has generally been classified as normal to above normal across most regions. In Shewa Zone along the Awash River, over 5,000 people were displaced and more than 2,400 hectares of crops destroyed. According to the Addis Standard newspaper, Amhara, Meket Woreda, floods, hail, and landslides damaged some 6,000 hectares of farmland destroying already mature crop and affecting approximately 45,000families. Notable exceptions include the mid and lowland areas of eastern Oromia, particularly in the East Hararghe and West Hararghe zones, as well as in the Bale and Guji zones. Localized flooding and landslides were reported in certain southern regions. In most parts of Tigray, the current rainfall season has been characterized by a delayed onset, erratic in nature as well as poor spatial distribution which is likely to negatively impact overall crop production.

In Sudan’s Darfur region, a massive landslide was experienced in Tarasin village, following heavy downpour within a short period of time, claiming over 1,000 lives. In South Sudan, floods have displaced more than 100,000 people in Jonglei, Upper Nile, and Unity states. The inundated area has been gradually increasing since the season began in June. 

Despite the destructive impacts from flooding, favorable rains from mid-July has brought some benefits across these 3 countries. The rains have significantly replenished water resources and improved pasture conditions. Soil moisture has also significantly improved which may be critical for the late planted crops. In Sudan, despite conflict-related challenges, satellite-derived indicators such as NDVI show that rainfall has supported pasture regeneration. Similar improvements can be observed across northern Ethiopia, in the Afar region. In contrast, conditions in northwestern Somalia have remained relatively poor following a delayed onset and below-average June–September rainfall (Figure 4).

The eastern sector of the region including eastern Kenya, most parts of Somalia, and Somali region in Ethiopia are typically dry at this time of the year. However, concerns are high following a hotter-than-average lean period leading to rapid deterioration of available pasture and water for pastoral communities. This situation is further compounded by forecasts indicating below-average rainfall and above-average temperatures during the October–December season which is regarded as the main season for these regions. 

There are significant concerns across the eastern Horn of Africa following a below-average October–December 2025 rainfall forecast issued by multiple climate models (Figure 5). This outlook is particularly concerning for regions in eastern and northern Kenya, eastern Ethiopia and much of Somalia. High temperatures in the June–September dry season led to rapid deterioration of pasture and surface water. Poor cropping conditions were also observed across the marginal agricultural zones of Kenya, Belg cropping regions of Ethiopia and the southern cropping zones of Somalia during the March–May rainy season. Below-average OND rains may delay pasture recovery leading to continued stress on livestock. 

The below-average OND rainfall forecast is associated with a high likelihood of La Niña developing and a present negative Indian Ocean Dipole (IOD) which is likely to persist through November. Historically, La Niña and negative IOD conditions tend to limit moisture flow inland resulting in below-average rainfall across eastern East Africa.

The GFS week 1 and week 2 forecast ending 21^st October indicate a slow start to the short/Deyr rains with little to no rain expected across northwestern and eastern Kenya as well as southern Somalia. The Western sector of the region including Uganda, Rwanda, Burundi as well as central and western Kenya is likely to experience a timely onset. These conditions are likely to persist as the season becomes fully established in November (Figure 6).