Coastal Floridians, Georgians and Carolinians were heading for higher ground Monday as Hurricane Dorian trudged toward the US’ southeast coast — while officials announced Monday the storm has been downgraded to a still-dangerous Category 4 hurricane.

“The window to prepare is closing,” tweeted Peter Gaynor, acting director of the Federal Emergency Management Agency. “If you are on Florida’s east coast, finish preparing & evacuate if local officials tell you to. Don’t tough it out – get out!”

FEMA is encouraging those on the coast to expect extreme winds, and to evacuate if instructed.

Mandatory evacuation orders are in place for coastal communities in 10 Florida counties comprising nearly all of the state’s Atlantic coast.

South Carolina Gov. Henry McMaster on Sunday ordered his state’s entire coastline to evacuate. The order, which was expected to take effect at noon Monday, will affect some 830,000 people.

Georgia Gov. Brian Kemp ordered evacuations for his state’s coast, also effective as of noon Monday.

Florida, Georgia, South Carolina and North Carolina have all declared states of emergency ahead of landfall.

Meanwhile, Fort Lauderdale-Hollywood International Airport announced it would be closing at noon, telling potential flyers to stay away.

“Please remember that the airport is not a shelter,” read a statement posted to the airport’s Twitter account. “The airport will reopen when it is safe to do so for our employees and passengers.”

Daytona Beach International Airport is set to close at 6 p.m.

Miami’s National Hurricane Center said Monday morning that Dorian’s maximum winds clocked in at 155 mph, taking the extremely dangerous storm down a slight notch from a Category 5.

Though Dorian continues to ravage the Bahamas, experts predict the eye of the storm by late Monday will be “dangerously close” to Florida’s east coast, where it’s expected to swirl through Wednesday.

With Post wires