The forecast of nearly a foot of snow was enough to shut down much of Washington on Monday, with the federal government closing its offices in the capital area.

Snow began falling in the capital early Monday, and officials warned people to stay off treacherous, icy roads. Schools were canceled, bus service was halted in places and federal government workers in the DC area were told to stay home on Monday.

The latest frigid blow of the harsh winter threatened as much as 10 inches (25 centimeters) of snow by the end of the day in Washington, Baltimore and elsewhere in the Mid—Atlantic region. Up to 6 inches (15 centimeters) of snow was predicted to the north in Philadelphia, while nearly a foot (30 centimeters) of snow was expected in parts of New Jersey.

Virginia Gov. Terry McAuliffe declared a state of emergency.

School systems in Baltimore, Washington and many suburban areas were closed, as were all Smithsonian museums except for the National Air and Space Museum. However, the U.S. Supreme Court was expected to be open and had arguments scheduled for Monday.

The wintry precipitation moved across much of the nation Sunday, bringing a mix of freezing rain and heavy snow to central and eastern states. Authorities warned of possible power outages and flight disruptions from weather that could affect millions.

More than 2,200 flights in the United States were canceled early Monday, according to flight tracking site FlightAware.com. The bulk of the problems were at airports in Washington, New York and Philadelphia. There are more than 30,000 flights in the United States on a typical day.

More In: World | International | News