The Capitol Building the evening after a snow. (Preston Keres/The Washington Post)

At least a dusting of snow is expected to blanket the Washington region on Thursday night and usher in one of the coldest days in a year in the nation’s capital.

By Friday morning, those returning to work and school will awake to lows in the 20s, but temperatures will feel much worse, meteorologists said. Winds gusting up to 30 mph will keep the wind chill in the single digits across much of Maryland, the District and Northern Virginia.

Leading up to that cold, the Washington region will teeter on the southern edge of much heavier snow fall expected in the Northeast overnight Thursday. The region could potentially see accumulations of 1 to 2 inches, with an outside chance for more, said Jason Samenow, chief meteorologist for the Capital Weather Gang.

Mixed with gusting winds, however, any accumulation could complicate the Friday morning commute. State highway officials in Maryland said they would begin treating roadways Thursday in advance of the storm, fearing rain on the leading edge of the storm could also leave roads icy as temperatures drop.

By sunrise on Friday at Reagan National Airport, the National Weather Service has predicted the wind chill will be 5 degrees — at least the coldest day since Jan. 24.

The punishing cold that will follow for much of the day could be hazardous for children waiting outside for buses, school officials warned. In Internet postings Wednesday night, some district officials began urging parents to take extra precautions in bundling up, especially young children.

In the District, the extreme lows will also pose the biggest challenge so far this winter for city officials charged with protecting the city’s homeless.

The District’s Hypothermia Shelter Hotline on Wednesday night warned that temperatures would soon reach dangerous lows, and urged those in need to make preparations or to reach out for help.

When temperatures first dropped below freezing in November, the hotline received 300 calls in a 24-hour period and the city sent out nine vans to give people rides to shelter and to deliver blankets and other comforts to those who opted to stay on the streets.

Under D.C. law, every one in the city is entitled to shelter during a hypothermia emergency, the city must place people in shelters, or, if there is not room, put them up in hotels. The city’s Hypothermia Shelter Hotline is (202) 399-7093.