Hurricane Isaias has ripped shingles off rooves and blew over trees as it carved its way through the Bahamas and headed towards the Florida coast, where officials in Miami said they were closing beaches, marinas and parks.
Miami Mayor Carlos Gimenez said Friday that 20 evacuation centres were on standby that could be set up with COVID-19 safety measures.
"We still don't think there is a need to open shelters for this storm, but they are ready," he said.
Authorities in North Carolina ordered the evacuation of Ocracoke Island, which was slammed by last year's Hurricane Dorian, starting Saturday evening.
Meanwhile, officials in the Bahamas evacuated people on Abaco Island, who have been living in temporary structures since Dorian. People living in the eastern end of Grand Bahama were also being moved.
Isaias had maximum sustained winds of 135km/h early Saturday and some strengthening was possible later Saturday, the US National Hurricane Center in Miami said.
The storm was centred about 185 kilometres south-southeast of Nassau in the Bahamas and was moving northwest at 23km/h.
Paula Miller, Mercy Corps director for the Bahamas, told The Associated Press that while the islands can normally withstand strong hurricanes, some have been destabilised by the coronavirus pandemic and the damage caused by Dorian.
A hurricane warning was in effect for Florida's east coast from Boca Raton, just north of Miami, about 240km north to the Volusia-Brevard county line. A hurricane watch was in effect from Hallendale Beach to south of Boca Raton.
Florida Governor Ron DeSantis said the state was "fully prepared for this and any future storm during this hurricane season", with stockpiles of personal protective equipment, generators, bottled water and meals ready to be distributed.