A voluntary evacuation order was in place for a second barrier island, Ocracoke. Gov. Pat McCrory warned residents of the Outer Banks and tourists to be careful until the storm passes.
"This is no time to put your stupid hat on," he said in a Thursday morning appearance on CNN.
Arthur, the first named storm of the 2014 Atlantic hurricane season, officially became its first hurricane early Thursday. At 11 a.m. EDT, the hurricane's center was 260 miles southwest of Cape Hatteras and 110 miles south-southwest of Cape Fear, packing maximum sustained winds of 90 mph.
The National Hurricane Center in Miami expects Arthur to grow into a Category 2 hurricane and then to weaken quickly as it moves up the east coast, staying offshore.
The storm was moving north-northeast at 10 mph. A hurricane warning was posted for North Carolina from Surf City to the Virginia border with tropical storm watches and warnings in place for much of the east coast.
Arthur has already disrupted plans for the July Fourth weekend in many cities. The traditional Boston Pops concert and fireworks display on the Charles River has been moved to Thursday night, although in Washington, where any rain brought by Arthur is expected to end by nightfall Friday, the July Fourth celebrations are still on track.
Rich MacDonald, an organizer for Boston's celebration, said the concert could still be canceled if there is rain Thursday.
"It affects the instruments, and these instruments are valuable and old," he told WCVB-TV.
In North Carolina, some beach-goers appeared unfazed by Arthur.
"We were banking on a couple of hours today before the storm moves in," Derek Cornwall told CNN as his daughter, Hannah, played in the surf in Atlantic Beach.
Surf City, N.C., canceled its Thursday night July Fourth celebration but advised vacationers good weather is expected once Arthur moves on. Officials warned, however, that dangerous surf and rip currents could make the water dangerous for some time and said visitors should have their fun on land.