Snow fell on areas north and south of the District on Tuesday, and while the snow has stopped in most places, temperatures are falling across the region.
Drivers and pedestrians should beware Wednesday morning of patchy ice, as temperatures drop.
Frederick, Loudoun and northern Montgomery counties saw snow Tuesday. The windchill is expected to be in the 20s all day Wednesday.
The wintry mix of snow and rain prompted many school systems to close or open with delays Tuesday.
Schools in Anne Arundel, Frederick and Montgomery counties in Maryland were on a 2-hour delay Tuesday. In Virginia, Loudoun County Public Schools were closed while Prince William County Public Schools operated on a 2-hour delay.
Expect delayed starts north of D.C. again Wednesday as the falling temperature overnight will mean ice and dangerous driving conditions.
Federal agencies in the D.C. area were open, but employees had the option for unscheduled leave or unscheduled telework, the Office of Personnel Management announced Tuesday morning.
A winter weather advisory will be in effect for the D.C. area until midnight Tuesday.
The storm is expected to be over by Wednesday morning.
D.C. spent the overnight hours working to prevent a repeat of Jan. 20, when an inch of snow and ice snarled traffic for hours ahead of the Blizzard of 2016.
"We don't want to get caught by surprise in case we get an earlier storm than predicted," said Chris Geldart, director of the D.C. Homeland Security and Emergency Management Agency.
The rain preceding the snow can complicate efforts to melt the snow, Virginia Department of Transportation administrator Steve Shannon said. It washes the brine away, so VDOT overcompensated by bringing in additional trucks.
VDOT crews treated interstates and major roads in Fairfax, Loudoun and Prince William counties. About 1,450 trucks were deployed along interstates, main roads and neighborhood streets Monday night and are remaining on duty to plow and treat roads through Tuesday.
Maryland State Highway Administration spokesman David Buck said crews pretreated roads Sunday.
Metrorail, Metrobus and MetroAccess service are operating on their regular weekday schedules.
Expect some flights from Baltimore-Washington International Thurgood Marshall Airport to be canceled, officials said Monday night. Travelers are advised to check with airlines before heading to the airport.
Pepco said in a statement Monday night that its crews were prepared to respond to any power outages.
"Pepco has about 150 linemen, 200 contractors and 200 tree crews available to respond to any outages that occur and, depending on the severity of the storm, can bring in additional resources," the company said.
Dangerously cold air is expected for the remainder of the work week. Expect highs in the upper 20s Thursday with wind chills of 10 to 15 degrees. If you plan to go out Saturday to celebrate Valentine's Day, be ready for some of the coldest air of the season, with single-digit wind chills and an overnight low of 10 degrees.
The Associated Press contributed to this report.