The approach of the new hurricane comes as the US government warns that clean-up efforts could take years after Hurricane Helene.
Hundreds of roads in affected areas remain closed, hampering efforts to send aid to hard-hit communities.
It made landfall in late September as a category-four hurricane – damaging structures, causing flash flooding and knocking out power to millions of homes.
As well as in Florida, deaths were recorded in Georgia, South Carolina, Tennessee and Virginia – and the worst-hit state, North Carolina.
President Joe Biden has ordered another 500 soldiers to be deployed to North Carolina. The troops – who now number 1,500 in all – will work with thousands of government relief workers and National Guard.
Biden has so far approved nearly $140m (£107m) in federal assistance. The use of the money has become the subject of false claims by Donald Trump, the Republican candidate for next month’s presidential election, who said relief money had been spent on migrants.
Trump has been accused of “dangerous” misinformation by the head of the US disaster relief agency.