"Torrential rains continued in several parts of Sudan... leading to flooding, landslides, damages to houses and infrastructure in at least 14 of the [country's] 18 states," the UN's Office for the Coordination of Humanitarian Affairs (OCHA) said.
"More than 50,000 people have been affected," it said in a statement. "The numbers are expected to rise."
Interior Minister Eltrafi Elsdik has said at least five people were killed and almost 3,500 homes damaged by floods last week.
Torrential rains often hit Sudan between June and October, resulting in heavy flooding. Last week's downpours burst a dam in Blue Nile state, destroying more than 600 houses.
"Last year, we had over 400,000 people affected during the whole season," said Saviano Abreu, the OCHA spokesman in Sudan