During its meandering path, Freddy’s highest sustained wind speeds have reached about 160 miles per hour, the equivalent of a Category 5 hurricane, as such storms are known when they form in the Atlantic.
As Freddy continued to swirl between Mozambique and Madagascar, the World Meteorological Organization, a United Nations agency, said that it was on track to become the longest-lasting tropical cyclone on record. The organization has set up a committee to evaluate whether Freddy had surpassed the previous mark, set by a tropical cyclone called John in the Pacific in 1994, taking into account Freddy’s shifts in intensity.
Scientists have found that climate change is making furious tempests like Freddy more common. Just over a year ago, the same area was hit by Cyclones Batsirai and Emnati, killing at least 120 people in Madagascar as the two storms followed in quick succession.
Mozambique was bracing on Thursday for Freddy’s return. As well as the 10 deaths in the country, around 9,900 people were displaced from their homes, according to the United Nations Office for the Coordination of Humanitarian Affairs.
Villages in Mozambique were cut off by fallen trees or burst river banks as the storm unleashed its fury, with estimates of some 28,300 houses destroyed. In the worst-affected areas, such as the port city of Beira, people waded through waist-high water to reach drier ground or help rescue efforts.
The authorities in Mozambique say they fear that 1.75 million people could be affected by the cyclone when it returns, and aid agencies have urged people to remain in shelters for a few more days.
The indirect impact of Freddy has been felt across southern Africa, where summer rains have dried up as the cyclone sucks moisture from the Indian Ocean, Mr. Venter, the forecaster, said.
The trail of devastation also brings a heightened risk of disease. Mozambique was already battling a cholera outbreak, with more than 7,500 cases reported. Floodwaters could destroy clinics and help spread the illness, the World Health Organization in Africa warned.
Judson Jones contributed reporting from Atlanta.