As of 5 p.m. ET, Irma was centered about 10 miles east of Albany, with maximum sustained winds up to 50 mph.
After flying over the Keys Monday, Florida Gov. Rick Scott described overturned mobile homes, washed-ashore boats and flood damage.
Tropical Storm Irma no longer exists but she left plenty of problems in SC.
On Sunday, Mayor Kasim Reed briefed the media on the city's preparations for the storm.
Some 6.5 million people, about a third of the state's population, had been ordered to evacuate southern Florida to shelters, hotels or relatives in safer areas. That risk extended to the coast of Georgia and parts of SC.
Irma is plowing into Georgia and toward other parts of the Deep South - Alabama, Tennessee and the Carolinas.
Although preliminary data suggest Irma's eye pushed a surge of more than 10 feet (3 meters) onto southwest Florida's Marco Island, the highest water levels were reported hundreds of miles away in Jacksonville and Savannah, Georgia, according to the National Oceanic and Atmospheric Administration.
Irma's rampage across Florida broke records in Jacksonville before heading north to torment Georgia and beyond.
That's what Gus Beyersdorf, 40, and his colleague Nick Jensen, 32, utility workers from Wisconsin, found out while inspecting power lines in Florida on Monday.
A third death in SC has been attributed to Hurricane Irma. People in these counties can expect winds of 70 to 90 miles per hour. Another man was killed in Sandy Springs, an Atlanta suburb, when a tree fell and "literally cut the home in half", said Sharon Kraun, the city's communications director.
And southwestern Florida, which is prone to surges, saw the opposite at first: a strange-looking negative surge that sucked the water off the sea floor quickly enough to maroon several manatees.
Georgia Gov. Nathan Deal has already declared a state of emergency for all 159 counties as Irma barrels toward the state. Officials said there was no immediate sign of serious damage to the 42 bridges that link the islands, but they were still checking. North Carolina: More than 166,000 customers, according to Duke Energy South Carolina: 233,000 customers, according to Duke Energy and SCE&G.
In Charleston, waters in the harbor peaked at almost 10 feet high, the SC city's third-highest reading, topping Hurricane Matthew in 2016, said CNN meteorologist Taylor Ward.
That's because some islands are extremely hard to access. The storm's size is another major factor, as with Katrina, said Jamie Rhome, who heads the storm surge unit at the National Hurricane Center.
Irma turned Jacksonville's Memorial Park into an unrecognizable lake.
Irma hit the United States soon after Hurricane Harvey, which plowed into Houston late last month, killing about 60 and causing some $180 billion in damage, largely through flooding.
Speaking at a ceremony at the Pentagon to mark the 16th anniversary of the September 11th terrorist attacks, president Donald Trump pledged the full resources of the federal government to help those affected by the recent flooding.
This is the first time two Category 4 landfalls occurred in the continental United States in the same hurricane season. Southbound US Route 1 - the only road connecting the Keys - is closed, Florida Keys spokesman Andy Newman said.