A significant thaw of snow and ice is unlikely to occur in the midlands or east of the country until the end of next week, Met Éireann has said.
Snow falls will become less frequent over the coming days but subzero temperatures and accumulations of compacted ice will make conditions even more dangerous for motorists and pedestrians.
The National Roads Authority said salt supplies for gritting roads were at an adequate level and the chairman of the Government's emergency taskforce has estimated that some 5,000 people are involved in the response to the severe weather each day.
Taoiseach Brian Cowen paid tribute to those who had contributed to the effort. "It is at times like these that the true sense of public service shines through. I believe it is important that these efforts are acknowledged," he said.
The majority of public transport services are operating today, with only a small number of bus and rail services across the country curtailed or cancelled because of the difficult conditions.
At a briefing by the taskforce today, Met Eireann's head forecaster Gerard Fleming said temperatures would again fall below zero tonight but not to the severe lows recorded recently.
However, he said the respite would be brief and that temperatures were likely to fall to minus six or seven degrees again on Saturday and Sunday night.
Mr Fleming said an air temperature of minus12.9 degrees was recorded in Carlow last night and that a ground temperature of minus 15.3 degrees was noted at the weather station at Casement Aerodrome in Dublin.
Forecasters at Casement also measured 21cm of snow last night, which Mr Fleming said was the third highest accumulation on record, surpassed only by extreme weather events in the winters of 1978-79 and 1962-63.
"This gives some idea of the exceptional conditions we are facing," he said, adding that the severe weather had come very early by normal standards.
Seán Hogan, chairman of the emergency taskforce, said the change from snow to more severe cold would pose its own selection of problems with compacted ice making conditions dangerous for both pedestrians and motorists.
"Conditions underfoot and on the roads will be even more dangerous when the snow has passed," he said.
Seán O’Neill of the National Roads Authority said certain areas had been hit harder that others and that five times the usual amount of salt had been used over the last week. He said that there was 30,000 tonnes of salt nationally and that local authorities had been asked to use a 50-50 mix of salt and grit in order to extend the supply to get them through the cold spell and keep roads open.
Dublin airport is open following extensive snow and ice clearance of the main runway and taxiways overnight. However, intending passengers are advised to consult their airline before travelling to the airport.
Irish Rail says Intercity, Dart and commuter services are operating, but there is a fifteen to thirty minute delay to city centre services after a points failure at East Point in Dublin. A bus is operating from Dunboyne to the Phoenix Park Station. The Docklands Station is closed.
The Luas is now operating an almost full. The Red Line is running from the Red Cow to Point but the Connolly Station stop is closed because of the conditions.
The Green Line is operating between Sandyford and St Stephen's Green only. A replacement bus service is running between Sandyford and Brides Glen.
Dublin Bus and Bus Eireann services are operating with curtailments and diversions on some routes. Bus Eireann said 95 per cent of its services were running today.
Dublin Bus said its Nitelink services will not operate tonight because of the conditions.
There are reports of a bus stuck on Wendell Avenue in Portmarnock. Motorists are advised to use an alternative route.
Heavy fog and black ice have been reported on the M9 Dublin/Waterford Road in both directions between J2 Kilcullen and J4 Castlewarden. Extreme care is needed on the M7 Dublin/Limerick Road through Co. Kildare particularly between J12 Newbridge and J14 Monasterevin/Athy where black ice and fog has been reported.
Treacherous conditions are reported around Maynooth and Kilcock. Boggan Hill in Carlow town is impassable and all roads in the town are hazardous. It is dangerous on the N2 Dublin/Monaghan Rd at Ashbourne, Slane and Collon and all hills.
Conditions are very poor on the old N3 (R147) between Kells, Navan, Dunshaughlin and Dublin. The Nine Mile Stone Road through Ratoath to Dunshaughlin is barely passable.
It is extremely treacherous in all parts of Co Wexford with refrozen snow and black ice the biggest problem for motorists. Wicklow town is treacherous as compacted snow and black ice make for hazardous driving conditions. The Sally Gap and Wicklow Gap are closed. All routes in Mullingar and Athlone are treacherous. The Kinnitty/Mountrath (R440) Road is closed.
Conditions are also poor on the M8 Dublin/Cork Rd between J6 Thurles and J10 Cashel and in parts of Waterford City. The N25 Soutth Ring Road in Cork city is closed due to numerous crashes and abandoned cars near the old Kinsale flyover and the route is treacherous from Midleton to Cork City. Blackstone Bridge should be avoided.