At least 100 people have died since October following El Niño rains in Kenya.
An estimated 70,000 others have been displaced by the resulting floods, according to a report by the UN Office for the Coordination of Humanitarian Affairs (OCHA).
The displacements mostly took place in Tana Delta, Nyanza, Garissa and Turkana.
The displacement is, however, significantly lower than expected, the report by OCHA released on Wednesday notes.
More than 1,400 families are at risk of landslides in highland areas, while another 1.5 million are at risk during the short rains season that begun in October.
Currently, six counties have active cholera outbreaks as a result of the floods, while about 1,000 acres have been inundated in Kisumu, Mwea, Garissa, Migori, West Pokot, Isiolo, Tana River and Mandera.
The enhanced rainfall has favoured arid and semi-arid areas with good pasture, crop development and has also replenished some water sources.
The report, on the effects of the El Niño phenomena in the Horn of Africa region, indicated the adverse climatic condition would result in famine.
This is as a result of the flooding, which will destroy crops, leaving at least 300,000 people in Kenya at risk of suffering food insecurity.
However, the OCHA report notes that Kenya has not provided any data showing the kind of response the government has put in place to combat the predicted drought.
“The number of cases of severe and moderate acute, malnutrition among children has also significantly increased in Ethiopia, Somalia, South Sudan and Kenya and this trend is likely to persist over coming months,” said Mr Pete Manfield who is in charge of OCHA in eastern Africa.
El Niño has had diverse effects in various countries in the Horn of Africa, the report shows, with floods in Kenya, Uganda and parts of Somalia and Ethiopia.
Conversely, drought conditions have been reported in parts of Ethiopia and Sudan and drier-than-average conditions in parts of Eritrea, Greater Upper Nile region of South Sudan, parts of northern Uganda and parts of Somalia.
In total, 18 million people in the eastern Africa region are at risk of being food insecure and the number is expected to rise significantly in 2016 due to the lasting effects of floods which will affect harvests.
PEOPLE AT RISK
Ethiopia has the highest number of people at risk of lacking food (10 million) followed by South Sudan, with 2.4 million people, while 120,000 people will face the same fate in Djibouti.
“The considerable humanitarian requirements are expected to remain at the current scale throughout much of 2016 until the majority of the affected people starts gradually recovering,” added Mr Manfield, during the presentation of the report at a Nairobi hotel.
Speaking during the same event, Dr Guleid Artan, the director of Igad Climate Prediction and Applications Centre (ICPAC) said the El Niño effects are likely to persist in 2016, with continued dry conditions in Sudan, South Sudan, most of Ethiopia, Eritrea, northern Somalia and Djibouti.
At the same time, there are likely to be increased chances of rains with high risk of flooding in parts of Uganda, Kenya, southern Ethiopia, southern parts of South Sudan, Rwanda, Burundi, Tanzania and the southern half of Somalia.