The State’s 4,000 primary and secondary schools have been ordered to close for three days from next Monday because of the adverse weather.
Minister for Education Batt O'Keeffe announced the measure this evening following a meeting of the Government's National Emergency Response Committee.
Mr O’Keeffe said he took the decision over concerns for the health and safety of school children in the “challenging” weather conditions.
"While it may be that some schools would have been in a position to open depending on the weather, I consider on balance that the responsible and prudent approach at this stage is to close schools in the interest of safety,” he said.
Met Éireann earlier issued a further severe weather alert, warning the Arctic conditions are likely to get worse over the weekend with up to 10 centimetres of snow forecast in some parts.
Urging people to take precautions, the forecaster said there would be “bitterly cold, icy conditions” countrywide over the next three days with freezing fog lingering in places and becoming widespread overnight.
“Another spell of snow will affect mainly Leinster and Munster during Sunday and Monday with falls of 5 to 10 centimetres expected,” it said.
Air temperatures are as low as -13.7 degrees and road temperatures are down to -10.4 on the N2 at Monaghan.
Motorists are again being urged to avoid unnecessary journeys due to treacherous road conditions and dense fog in many parts of the country.
Met Éireann's warning comes as transports chief said shrinking supplies could lead to the closure of major routes.
With forecasters predicting no significant thaw for at least seven days, the National Roads Authority said stocks of salt were already at extremely low levels.
“We have about 6,000 to 9,000 tonnes coming in next week and we’re going through 20,000 tonnes a week so it is an issue,” a spokesman said. “Local authorities are going to do the best they can. Currently no major roads are closed, but with supply and demand you may have to close a road,” he said.
Gritters are out on many main roads but secondary roads remain icy and treacherous.
A shipment of 4,000 tonnes of salt arrived in the Shannon estuary earlier today from Tees Port in the north east of England.
The consignment, the third shipment in as many weeks, was to be handled at the Limerick Port but had to be diverted to the Foynes Port, some 40 kilometres away, due to freezing fog along the estuary.
Local authorities from the west, north west, south and midlands, including counties worst hit by the prolonged freezing weather, were today urgently awaiting consignments of salt from the shipment.
Fine Gael today called for motorway tolls to be temporarily lifted during the current cold spell.
Party TD Shane McEntee said: “The Government should open negotiations with motorway operators in order to lift the tolls until the current weather crisis is over. . . . At the very least, the Government should lift the tolls on the M50 and the Port Tunnel which are still in State ownership.”
Hundreds of schools around the country remained shut today, while Bus Éireann experienced disruption on local services on some secondary routes.
Bus Éireann said the most of its services would be operating with some delays this weekend.
However, a company spokesman said services were dependent on weather and road conditions which were being assessed on an hourly basis.
Dublin airport remained open and operated normally today, but passengers are advised to consult airline websites or their airline directly before travelling to the airport.
A Dublin airport spokesman said tonight that snow and ice crews were working on a 24 hour-basis to clear the runways and taxi areas.
Iarnród Éireann said all rail services operated as normal across the network today despite the freezing conditions. A spokesman said they were expecting busy numbers on intercity routes this weekend because of the road conditions, and advised people to book online and allow additional time to get to their train stations. Any disruption to services would be posted on www.irishrail.ie/news_centre.
Eircom said weather conditions had caused severe disruptions to its telephone network across the country. The company said the current number of faults stands at 5,134, with some 1,757 reported in the last 24 hours.
It said its technicians would work throughout the weekend to restore service to customers as soon as possible.
Demand for electricity has been increasing over the past 24 hours due to the freezing temperatures, according to national operator EirGrid.
The company's control centre recorded new peaks in demand yesterday and today, but EirGrid added this rise in demand is being managed in the normal workload.
Dublin City Council has urged the public to conserve water during the cold weather following a number of broken mains.
“Water demand has remained at a very high level since before Christmas. A further sharp increase has occurred since the beginning of January. Demand is currently running at a higher level than at any stage in recent years,” it said.
In Meath, the N2 is icy at Ashbourne but all lanes are open. There is freezing fog around Trim. Secondary roads remain treacherous especially around Slane, Trim, Kells, Athboy, Oldcastle, Julianstown, Laytown and Ratoath.
In Kildare, there is bad fog on the M4 from the toll plaza to J5 Leixlip. Main roads are being gritted.
There is also dense fog around Longford town and in Abbeyleix, Co Laois.
In Dublin, housing estates are reported to be extremely icy and there is still a thick frost on most roads in the suburbs and in many parts of the city centre. Motorists are advised to avoid any unnecessary journeys.
Tonight's temperatures will fall to range from - 3 degrees near coasts to as low as -13 degrees inland.