BOSTON — A winter storm that dropped nearly 2 feet of snow just north of Boston, temporarily shut down major highways in New York and Pennsylvania and forced airlines to cancel thousands of flights nationwide menaced the Northeast on Friday with howling winds and dangerously cold temperatures. The storm was blamed for at least nine deaths in the eastern half of the country.

The nor’easter — which brought plummeting temperatures that reached 8 degrees below zero in Burlington, Vt., early Friday with a wind chill of 29 below zero — dumped 23 inches of snow in Boxford, Mass., by early today and 18 inches in parts of western New York near Rochester. Thirteen inches of snow fell in Boston, while Lakewood, N.J., got 10 inches and New York’s Central Park got 6.

On a mostly empty Main Street in Concord, N.H., Kathy Woodfin hustled to work, a tall iced coffee turning to caramel-colored slush in her left hand. It was 7 degrees at 9 a.m. and the wind zipping through alleyways blew a fine, stinging snow in her face.

“I just run from heated car to heated building,” the New Hampshire native said. “It’s just like down South, where they run from air conditioned car to air conditioned building.”

The snowfall, frigid temps and stiff winds extended the holiday break for some students in the Northeast for a second day while posing the first test for New York City’s new mayor and perhaps the last challenge for Boston’s outgoing one.

U.S. airlines canceled more than 2,300 flights Thursday because of the snowfall and low visibility. By Friday morning, about 1,600 flights were canceled nationwide, according to the aviation tracking website FlightAware.com.

Workers at a convenience store in Mount Laurel, N.J., said they were busy all night as they fueled plow drivers with coffee and other necessities.

Among those stopping in as the snow continued to fall before dawn was David Neff, a newspaper deliveryman. “It sucks out here,” Neff said. “They’re just starting to plow stuff. We definitely got what they said and maybe a little more.”

Forecasters had said much of New Jersey would get 4 to 8 inches.

Snow began falling overnight Wednesday in parts of New England and New York state, but the brunt of the storm began late Thursday. Forecasters warned that gusts of up to 30 miles per hour could bring wind chills to minus 25 degrees, cold enough to cause frostbite in about 30 minutes or less. The weather service said people should dress warmly to avoid hypothermia and cover all exposed skin.

Governors in New York and New Jersey declared states of emergency Thursday, urging residents to stay home. State and county government offices in Delaware were closed Friday. Massachusetts Gov. Deval Patrick said state offices that closed early Thursday would remain closed Friday. He said Friday morning he was concerned about coastal flooding at the mid-day high tide and “extreme” low temperatures expected to continue into Friday night.

New York Gov. Andrew Cuomo ordered three major highways closed overnight. The Thruway between Albany and the Bronx, the Long Island Expressway and Interstate 84 between the Pennsylvania and Connecticut borders all reopened Friday morning. Southbound Interstate 95 closed in Philadelphia for several hours because of a jackknifed tractor-trailer.

The heavy weather began rolling in just a day after New York Mayor Bill de Blasio was sworn in to lead the nation’s largest city and a few days before Boston Mayor Thomas Menino ends 20 years in office on Monday.

De Blasio, who as public advocate in 2010 criticized his predecessor Mayor Michael Bloomberg for his handling of a large snowstorm, dispatched hundreds of plows and salt spreaders on the streets as soon as the snow started falling Thursday night. The New York metropolitan area got between 6 to 11 inches of snow.

This morning, de Blasio was shoveling the sidewalk outside his Brooklyn home. Wearing a black jacket and gloves, he joked with reporters and demonstrated proper shoveling techniques. He later brought out salt to spread on the walk.

Across the region, state and local police were busy responding to accidents and reports of stranded vehicles.

Amtrak was running trains on all of its Northeast lines on Friday but operating on a modified schedule, spokeswoman Christina Leeds said. Commuter trains Metro-North Railroad, which runs trains between New York City and suburban Connecticut, Long Island and New York’s Hudson Valley, the Long Island Rail Road and New Jersey Transit were operating on weekend schedules. Chains were placed on New York City buses so they would not get stuck in drifts.

Slick roads were blamed for traffic deaths in Michigan, Kentucky, Indiana and Illinois. Authorities said a 71-year-old woman suffering from Alzheimer’s disease froze to death after she wandered away from her rural western New York home.

As the storm approached, a worker at a suburban Philadelphia salt storage facility was killed when a 100-foot-tall pile of road salt fell and crushed him. Falls Township police said the man was trapped while operating a backhoe. There was no word on what may have caused the accident.

The snowstorm worked its way east from the Midwest, where it dropped up to a foot of snow on Michigan and more than a foot in parts of Illinois, prompting the cancellation Thursday of hundreds of flights at both Chicago airports. It merged with low pressure moving northeast off the mid-Atlantic coast, forming a nor’easter.

Nearly 17 inches of snow fell in some of Chicago’s northern suburbs, and more than 12 inches of snow was recorded at Midway International Airport. About 10 Southwest Airlines planes were stuck on the tarmac at Midway for up to four hours amid flight backlogs.

In Wisconsin, a record low temperature was set Friday morning in Green Bay, where the mercury dipped to minus 18. The National Weather Service said that topped the 17-below-zero mark last recorded in 1979.