Before affecting Madagascar, officials in the country advised residents to evacuate to shelters, although the storm was not expected to be as severe as it was. When Manou stalled just offshore eastern Madagascar, it produced gusts as strong as in Vatomandry. The same city reported of rainfall in a 15‑hour period. Damage was heaviest in Vatomandry, where 85% of buildings were destroyed, although the broader region also experienced severe damage and was largely isolated from the rest of the country. In Vatomandry, Manou severely damaged the main hospital, several schools, and the prison. The storm disrupted power and water networks. Strong winds blowing salt spray destroyed the coffee and cloves crops, and rice crops were also damaged, after 80% of rice fields were flooded in Brickaville and Andevoranto. In those two towns, an official estimated that 95% of houses were wrecked. The road between Vatomandry and Brickaville was washed out or otherwise blocked by landslides, and the village of Ilaka was isolated after the storm wrecked a bridge. Throughout Madagascar, Manou injured 85 and killed 89 people, including 23 people in Vatomandry and 2 in Brickaville. About 24,500 houses were destroyed, leaving 114,480 people homeless.
