The president didn't waste any time either. He has declared an emergency in Virginia, New Hampshire, New Jersey, Connecticut, Massachusetts and Rhode Island, making federal aid available to bolster state and local responses to the storm. The presidential declaration authorized the Department of Homeland Security and the Federal Emergency Management Agency to coordinate all disaster relief efforts.
Joined by his wife, Michelle, and daughters Malia and Sasha, Obama boarded his Marine One helicopter at the island's airport late Friday and took off for Cape Cod, where Air Force One waited to take them back to Washington.
White House spokesman Josh Earnest said the president felt it prudent to be back in Washington when Irene strikes the Eastern Seaboard. Obama informed his staff shortly after urging millions of Americans in the path of the storm to heed instructions from state and local officials, especially if directed to evacuate.
"Don't wait, don't delay," Obama said. The storm was on course to rake the coastline from North Carolina to New England over the weekend.
The president, speaking from his vacation rental on the island, said the federal government is "bringing all federal resources to bear" in response.
"I cannot stress this highly enough, if you are in the projected path of this hurricane you have to take precautions now," he said.
Illustrating government preparations, Earnest said that the administration conducted a national exercise to test emergency preparedness in 2009. He said the exercise included a simulated hurricane that struck New York City. He said the president participated in that exercise.
Though Martha's Vineyard was in Irene's path, Earnest said Obama's decision to return to Washington Friday night, instead of Saturday as planned, was not made out of worry about his personal safety.
Obama has been vacationing in Martha's Vineyard since Aug. 18, though the holiday's been repeatedly interrupted amid the upheaval in Libya, Tuesday's East Coast earthquake and preparations for the new jobs and debt package Obama's unveiling next month.
Obama said he had been briefed on Irene's status Friday morning by top federal officials. He also talked to governors of states and mayors of communities in the expected hurricane path, including mayors Michael Bloomberg of New York and Michael Nutter of Philadelphia.
As the president spoke, rains from Irene's outer bands began hitting the Carolinas, along with 6- to 9-foot waves. On Martha's Vineyard, though, Obama stood in the shade of a poplar tree outside a gray-shingled cottage. Otherwise it was bright sunshine, not a cloud in the sky.
The president cited two government websites, one in English and one in Spanish, that provide advice on how to prepare for emergencies: www.ready.gov and www.listo.gov.
He said the Federal Emergency Management Agency has been deploying teams along Irene's projected path. The agency has millions of liters of water, millions of meals and tens of thousands of cots and blankets positioned along the Eastern Seaboard, he said.
And the American Red Cross has been preparing shelters in North Carolina and other states, he said.
Obama cautioned that it would take time after the storm to begin rescue operations and get resources to people in need.
"So the more you can do to be prepared now, making a plan, make a supply kit , know your evacuation route, follow instructions of your local officials, the quicker we can focus our resources after the storm on those who need help the most," he said.
"All indications point to this being a historic hurricane."
Two years ago, Obama's first vacation on Martha's Vineyard as president was delayed by Hurricane Bill.
The Associated Press contributed to this report.