Saturday's icy weather conditions cancelled and delayed dozens of flights going into and out of the region's airports.
All runways at Washington Dulles International Airport are back open after they were shut down due to Saturday's icy weather conditions.
The airport had reopened three of its runways by Saturday afternoon, but said on Twitter residual flight delays and cancelations were likely.
Passengers should check with their airlines to confirm the status of their flights, the airport advised.
Baltimore/Washington International Thurgood Marshall Airport said its airfield and public roadways were also being treated due to icy conditions. As of 4:20 p.m., BWI said it was still experiencing flight delays and cancelations and travelers should check with their airlines.
Ronald Reagan Washington National Airport said it was open and operating normally, but warned travelers that many roadways around the region were treacherous due to ice.
All Metrobus service was suspended until about 10:30 a.m. because of the dangerous road conditions. The Washington Metropolitan Area Transit Authority advised commuters to use Metrorail, if possible.