Hurricane Matthew's deadly force is bearing down on the United States.
Two people have been killed by falling trees, and another two died because emergency crews couldn't get through in the conditions.
The hurricane has pummelled the city of St Augustine, Floride with more than 22 centimetres of rain falling.
The southeastern US states of Georgia and South Carolina are bracing for a record-setting tide as Hurricane Matthew spins along the country's southeastern coast after delivering a deadly punch to the Caribbean.
The storm weakened late on Friday to a category 2 storm with maximum sustained winds of 175 km/h, the US National Hurricane Center said.
Matthew has moved to about 215km south of Savannah, Georgia, one of four US states under a state of emergency, including evacuation orders for residents living near the coast.
Officials in the region said their biggest worry was a storm surge of as much as three metres of water that could be pushed onto land.
"There is a danger of life-threatening inundation during the next 36 hours along the Florida northeast coast, the Georgia coast, the South Carolina coast, and the North Carolina coast," the Miami-based hurricane centre said.
The centre said the eye of Matthew remained just kilometres offshore. It is forecast to continue moving near the coast of northeast Florida and on to Georgia through Friday night. It is expected to move on to the coast of South Carolina on Saturday, the centre said.
As Matthew turns along the Georgia and South Carolina coastlines, its anticlockwise winds are going to hit the shore and cause the surge, said Florida Senator Bill Nelson on CNN.
US President Barack Obama on Friday urged citizens to listen to local authorities, and warned that storm surge remained an on-going threat.
The storm left about 600,000 homes in Florida without power. One of the hardest-hit areas in the state is Brevard County, located east of Orlando on Florida's coast, Governor Rick Scott said. About one-quarter of the homes without power were located there.
Millions of people have already evacuated coastal areas.
DPA / Newshub.