Highly variable seasonal conditions and developing El Niño signals concerns across East Africa

• The March–May 2026 rainfall season has remained cumulatively average to above-average across much of Ethiopia, Kenya, and South Sudan leading to favourable agricultural and rangeland conditions in these areas.
• March to early May rainfall totals in much of Uganda, Rwanda, Burundi are near average with some deficit areas. Rainfall is substantially below average in southern-central Somalia and southeastern Ethiopia where seasonal totals are as low as 45 percent of average.
• A dry period occurred during early-to-mid April, characterized by deficits across much of the region, including most of Kenya, Uganda, Rwanda, Burundi, and a delayed Gu rainfall season onset in Somalia. This raised concerns about negative impacts to crop production.
• Enhanced rainfall in late April improved soil moisture, and in many areas, this supported recovery of crops, pasture and surface water conditions. Due also to an early onset and above-average early-season rainfall, crop conditions across most bimodal cropping areas of Kenya, Uganda, South Sudan and Belg cropping regions of Ethiopia remain generally favourable. Pasture and water resources remain favourable across most pastoral areas of Kenya.
• Concerns about poor rainfall distribution and negative impacts continue in Somalia. While early May brought wetter conditions, below-average vegetation and moisture conditions persisted across Somalia and parts of eastern and southeastern Ethiopia, and seasonal rainfall deficits remained significant as the typical end of the season nears.
• There are concerns about likely below-normal June–September 2026 rainfall over parts of Sudan, South Sudan, the Kiremt-producing areas of Ethiopia, western Kenya, and Karamoja in Uganda associated with an early development of El Niño condition during the May–July period. Forecasted moderate to strong El Niño conditions and a positive Indian Ocean Dipole will likely lead to a wetter-than-normal October–December 2026 short rains season, with potential for extremely enhanced rainfall.

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 (April–June); long rains in unimodal Uganda and Rwanda, and unimodal and bimodal Kenya (March– November); Season B rains (mid-February to May) in Burundi; belg rains (mid-February to May) in Ethiopia, as well as the diraac/sugum rains in the northern pastoral areas and gu/genna rains in the southern and southeastern pastoral areas of Ethiopia; and the first season rains in the bimodal areas within southwestern Ethiopia, southwestern South Sudan, and northern Uganda.

The March–May (MAM) 2026 rainfall season has remained cumulatively average to above-average across much of Kenya, northern and southeastern South Sudan, and the western half of Ethiopia following wetter-than-average conditions since February (Figure 1). This sustained rainfall has enhanced soil moisture conditions not only in key agricultural zones across Kenya, Belg cropping region of Ethiopia and bimodal regions of South Sudan but also beyond the typical MAM impacted regions such as Kiremt growing regions of Western Ethiopia and unimodal northern South Sudan (Figure 2).

The enhanced rainfall has also resulted in localized flooding, especially in urban areas. In Kenya, flooding and landslides have been reported in parts of Elgeyo Marakwet, Tharaka Nithi, Kwale and Kiambu counties leading to fatalities and damage to road networks. In South Sudan, above-average rains in the northeast during April led to storm damages and a fatality in Malakal area.

In early-to-mid April, widespread rainfall deficits were observed across much of East Africa. The approximately 20-day dry spell occurred at the peak MAM season rainfall month of April, raising concerns over the conditions of already cultivated crops. This also marked a poor onset of the Gu rainfall season in Somalia, particularly in central and northern areas which are already experiencing cumulative multi-seasonal deficits. As of May 5^th, cumulative seasonal rainfall deficits persisted across southwestern and some central areas of Uganda, southern Rwanda, northeastern Burundi, and much of Somalia aside from the southwestern and northwestern areas. However, crop conditions across most bimodal regions of Kenya, Uganda, South Sudan, Rwanda, Burundi and Belg cropping areas of Ethiopia remain generally favourable (Figure 3). This is mainly because of the extremely above average February–March rainfall performance that raised soil moisture conditions to levels that helped sustain crop growth through the dry spell. In late April, rainfall conditions significantly improved across Kenya, much of Ethiopia and South Sudan, supporting favourable crop conditions. Uganda, Rwanda and Burundi remain cumulatively slightly below average but with much less concern given that they are high rainfall regions. However, continued deficits would limit crop production outcomes. Pasture and water resources remain generally favourable across most pastoral areas of Kenya.

In central and northern Somalia, the April–June 2026 season has so far been characterized by delayed and poorly distributed rainfall. Across Somalia and southeastern Ethiopia, rains during the first week of May brought some relief, and some improvement to vegetation and moisture conditions is expected during early-mid May. However, as of May 5^th, pasture and water conditions remain poor following a delayed onset and a persistent below-average Gu season (Figure 4). The erratic rains and a season that is likely to end on time will likely be followed by hotter-than-normal temperatures that would rapidly deteriorate vegetation conditions when the Gu rains subside.

CHIRPS-GEFS rainfall forecast for the first 2 weeks of May indicates some decent rainfall totals expected across the entire region apart from eastern Kenya (Figure 5). These amounts are likely to improve vegetation conditions in Somalia, Uganda, Rwanda and Burundi. Concerns about poor rainfall distribution in Somalia will continue. Gu season rainfall typically substantially declines in late May. Enhanced rainfall expected in the western half of Kenya is likely to heighten flood risk in low lying regions closer to Lake Victoria.

The current climate forecasts indicate a persistent likelihood of El Niño conditions developing during the May–July period (Figure 6). Historically, the early development of El Niño conditions has been associated with suppressed rainfall during the June–September period over parts of Sudan, South Sudan, the Kiremt-producing areas of Ethiopia, western Kenya, and the Karamoja region of Uganda. In Ethiopia, during past years with similar El Niño conditions, both maize and sorghum yields were below normal, with the greatest losses in eastern Amhara, Tigray, and northeastern Oromia. If the current El Niño development persists into the latter part of the year, there is an increased likelihood of enhanced rainfall during the October–December 2026 short rains season across much of eastern East Africa. This will be critical for bimodal regions of Kenya, Somalia, Uganda, Rwanda and Burundi.