Forty-five people have died in the arid west African country of Niger in flooding since June, and nearly 209 000 have been affected, the UN said on Tuesday.
The rains destroyed nearly 17 400 homes, killed more than 33 000 livestock and damaged crops, the Office for the Coordination of Humanitarian Affairs (OCHA) said.
Nearly 8 000 hectares of millet, maize and bean fields were inundated, it said.
The government had given a far lower figure, citing 469 people affected.
The three-month rainy season is coming to an end but it has caused flooding in many areas, including in the desert north.