Dublin Airport is battling to keep flights operating as commuter traffic across Ireland is crippled by the big freeze for a fifth day.
Bus Eireann and Dublin Bus were keeping most routes open on main roads but the capital's Luas tram was running limited services.
Heavy snow and compacted ice were blamed for increasingly difficult conditions.
Met Eireann also warned there is no sign of a let-up in the Arctic weather with the freezing temperatures expected to hang over the country for up to a week.
Forecasters also said between 5-10cm of fresh snow will hit much of the country during the day.
On a brighter note, the experts are predicting temperatures to begin to rise next Wednesday but it will be a slow shift from the Scandinavian-type weather.
Dublin Airport said it was fully operational on Friday morning after teams carried out extensive snow and ice clearance on the main runway, taxiways and associated apron area overnight. But passengers were again advised to check with their airlines.
Elsewhere, Irish Rail said its inter city, Dart and commuter services were operating normally. Bus services and travel by car were reported to be worst in the east of the country.
The Luas was limited to running between Sandyford and Beechwood on the Green line and Tallaght and Abbey Street on the Red line. It is understood thick ice on the tram tracks caused running problems.
Hundreds of schools, colleges and institutions remained closed, with up to one in five employees not making it to work in the cold.