Motorists have been warned to take extreme care this evening as temperatures are forecast to drop sharply, causing snow and slush on the roads to freeze.
Met Éireann is warning of a bitterly cold night with widespread severe frost. Further showers of hail, sleet and snow are also forecast in northern, western and eastern coastal areas.
Temperatures will drop to between 0 to minus 7 degrees this evening. The cold spell is due to last for a couple of days.
Motorists are being urged to reduce their speed significantly and to keep a safe distance from the vehicle in front of them.
AA Roadwatch said heavy snow overnight resulted in treacherous conditions in parts of Leinster today; in particular in parts of counties Wexford, Wicklow, Kildare and Meath. The M9 is closed northbound between Waterford and Mullinavat.
In Co Wicklow, the Sally Gap and Wicklow Gap are impassable due to the snow and drivers are advised to avoid the area. Very icy conditions have also been reported on the N11 between the Rathnew and Arklow exits.
In Co Kildare, motorists have reported treacherous conditions on the M7 Limerick/Dublin Rd at junction 12 Newbridge and icy conditions are reported in Navan, Laytown and Kentsown in Co Meath.
Road conditions in counties Sligo, Mayo, Galway and Donegal are reportedly treacherous and in many costal counties the snow has not thawed.
The State’s transport agencies; Dublin Bus, Bus Éireann, Irish Rail, RPA, DAA and NRA met with Minister for Transport Noel Dempsey today to co-ordinate their response to the severe weather.
There are a number delays to flights arriving and departing from Dublin airport this evening after the main runway was shut early this morning to allow ice and snow to be removed.
As a result, Aer Lingus has cancelled 32 flights and a spokeswoman said there were delays on a number of others. Passengers are advised to check the airline's website for updates. Ryanair's website also lists delays to a number of flights.
Commuters experienced travel problems due to the adverse weather with Dart services and Northern commuter, Belfast and Rosslare services cancelled earlier today.
Overnight lightning affected overhead rail power lines and signalling systems and disrupted Dart and Luas services this morning. Dart services are now operating normally.
Luas services are also operating normally after delays earlier caused by the weather and the protest march in the city centre.
Bus Éireann and Irish Rail said they will issue real time updates of disruptions via Twitter while the NRA is providing details of road closures.
Dublin Bus advises customers that the bad weather means a number of routes have been disrupted. These include routes 40b, 44b, 65 which are terminating early.
Commuters are advised to check their website (www.dublinbus.ie) for updates throughout the day.
