"Sheremetevo airport was not closed, it has been working and is still working as normal," an airport spokeswoman said. "Current visibility is more than five kilometers [3 miles]."
Earlier reports said that thick fog had forced authorities to close two out of three Moscow airports - Sheremetevo, Russia's main international hub in the north, and Vnukovo in the west - for arrivals and departures until 1p.m.
At least 15 flights to the two airports were redirected early Friday morning to reserve airports in Nizhny Novgorod and St. Petersburg in northwestern Russia, an official at Nizhny Novgorod airport said.
However, Vnukovo was later re-opened, airport officials said.