An aid group estimates that more than 1 million people in East Africa are affected by flooding after higher-than-normal rainfall.
Parts of the region are bracing for a tropical storm that could worsen an already dire humanitarian situation.
The International Rescue Committee on Friday said many people had been reeling from an earlier period of severe drought.
The rains in parts of Somalia, South Sudan and Kenya are expected for another four to six weeks.
South Sudan's president earlier this week declared a state of emergency in 27 counties because of the flooding.
Experts say the floods are a worrying sign of how climate change is affecting already vulnerable communities.
