Powerful rains that have swept the arid state of Niger since June have left 75 dead and affected 108,000 people, the government said on Tuesday.
The previous toll issued by the Civil Protection Agency on August 14 was 32 dead and nearly 67,000 affected.
The worst-hit regions are Maradi in the central south, Zinder in the central east, and Tillaberi and Tahoua in the west.
The landlocked Sahel state’s annual rainy season typically runs between June and August or September.
But in recent years, rainfall has become more intensive, accelerating the risk of deadly flooding in shantytowns.
More rain is forecast for the coming weeks, and the Niger Basin Authority has issued a warning for the capital Niamey, through which the Niger River flows.
Floods last year claimed more than 70 lives and affected more than 200,000 people. According to UN estimates, at least 350,000 could be affected this year.
The floods have combined with regional droughts and extremist attacks that have badly hit harvests.
More than 4.4 million Nigeriens -- around one in five of the population -- suffer from “severe” food insecurity, according to health monitors.