Storm force winds have caused chaos all over the country, blowing down trees, power lines, and telecoms networks.
More than 70,000 homes were left without power, and widespread travel chaos was expected to continue today as airports were forced to delay or divert flights, ferry companies cancelled sailings, and road networks were blocked by fallen trees and debris.
One of the worst hit areas in the country is Kerry where supply was knocked out to 25,000 but 10,000 of these have been reconnected.
The storm warning has been downgraded to a Code Yellow, which is the least severe weather warning, for the entire country.
There were dramatic scenes at Coláiste Cois Life in Lucan, Dublin when the roof was ripped off.
The principal of the Irish-language school Tomas O Donnagain is surveying the damage caused when gael-force winds sheared off a section of the school's roof this morning.
A section of the roof is hanging perilously, prompting school officials to keep bystanders away from the site in case it blows off in the strong winds.
Winds of more than 100 kilometres per hour ripped off a 30 foot by 30 foot section of the metal roof around 4am today. Some roof felt and insulation were blown all over the school yard.
The high winds also toppled many wheelie bins all around the country, creating obstacles on roads, and Iarnrod Eireann reported an incident where a trampoline that had been caught by the wind caused damage to overhead lines at Blackrock in Dublin, and another was hit by the 7.10am train from Waterford to Dublin at Kiltorcan but they have been cleared.
There are also delays of up to an hour on the Gorey-Dublin Connolly train service because of debris.
Pearse Street Train Station in Dublin is closed due to roof damage and will remain closed for the rest of the day. Trains are running through but not stopping at the station.
Iarnrod Eireann's spokesperson Barry Kenny said pieces of timber and "small bits of debris" has fallen down in the station.
He advised passengers to use either Tara Street or Grand Canal Dock until the storm has abated.
"We need the storm to abate before we can properly assess the situation."
Services from Heuston Station have also been affected by the weather. A fallen telegraph pole has been removed from the line between Hazelhatch and Sallins while some other unstable poles have been removed.
Services were expected to be back to normal by 11am.
More than 7,500 Eircom customers were without telephone and broadband service as a result of strong winds, heavy rainfall and lightning overnight.
The company said it expected the figure to rise as the bad weather continues.
Cork, Galway, Mayo, Kilkenny, Carlow and Wexford were among the areas where services were worst hit.
"Working conditions in many areas of the country remain extremely difficult as a result of the dangerously high winds and lightning," Eircom said in a statement.
"These conditions are hampering our repair efforts in some areas of the country."
It said 700 crews were working today to restore services to those affected.
Around 2,250 customers had their services restored between Christmas Eve and St Stephen's Day.
The Luas red line is not running between the Belgard and Tallaght stops, due to weather conditions as well.
Winds of up to 130kmh were recorded in the latest of a recent series of Code Red storms, with the south and west of the country bearing the brunt of the Atlantic weather front.
At Dublin Airport no flights took off early this morning due to cross-winds, and only a limited number landed.
The first flight out was after 7.30am, with airlines and air traffic control monitoring the situation on an ongoing basis.
“Some of the transatlantic flights were also diverted to the UK instead of landing in Dublin,” said a Dublin Airport spokeswoman.
The Dublin Airport Authority has said that severe gusts are affecting both departing and arriving planes, with a number of transatlantic flights having been diverted to either Heathrow or Manchester airports in the UK.
Five flights have been cancelled in total.
Siobhan Moore of the Dublin Airport Authority said: "The flight schedule has been severely disrupted this morning as a result of strong gusty winds blowing across both runway at up to 60-65 knots.
"So far there have been five flights cancelled, four have been diverted and there are a number of ongoing delays as a result and this will have an impact on the flight schedule for the rest of the day.
"The advice for passengers is to consult with their airlines before travelling to the airport."
In Shannon Airport, one Aer Lingus flight to Manchester has been cancelled but it is operating normally other than that.
Cork Airport is reporting flight delays but no cancellations.
PNO Ferries will resume sailings from 10.30am this morning.
Stena Line cancelled its 1.30pm sailing from Dun Laoghaire to Holyhead, while Irish Ferries cancelled its fast-ferry services to the same destination, advising customers to take its cruise ferries instead.
Its Rosslare to Pembroke sailing was also in doubt today.
The Gardai and Fire Brigade reported that trees had fallen “all over the country” - blocking roads and taking down power lines in the process.
“The list of locations for fallen trees is endless,” said one Dublin Fire Brigade controller, citing north county Dublin and its border with county Meath as particularly bad, with areas around Dunsaughlin and Dunboyne named as badly affected.
Parts of Sandyford in south Dublin were also affected by fallen trees and debris.
The Howth Road was closed at the entrance to the Deerpark Golf Course due to a fallen telegraph pole, and there were several trees downed on the Swords/Naul Road in north Dublin.
There was also a tree down at Churchtown Road Lower beside Milltown Golf Club, and also on the Eglinton Road/Sandford Road junction, on Willbrook Road in Kiltiernan.
Surface water from heavy rain had also made driving difficult inbound on Morehampton Road.
Very strong crosswinds were reported on the N11 Dublin to Wexford road in Wicklow.
In Wicklow a tree was blocking the Baltinglass to Ballytore road at Tinoran near Baltinglass.
In Tipperary the N65 Borrisokane to Portumna Rd was impassable due to several trees down on the road at different locations. Motorists wishing to travel from Borrisokane to Portumna should divert via Lorrah Village.
The Cliffs of Moher Visitor Centre will be closed today due to the extremely windy conditions.
While the winds were expected to moderate later today Met Eireann said it would remain windy in the east of the country, but that the calmer conditions would bring a drop in temperatures.
Gusts of almost 125kmh were recorded at Mace Head in Galway at 7am this morning.
This afternoon's fixture at Leopardstown will go ahead as scheduled, in spite of heavy overnight rain.
Officials at the Dublin circuit were on red alert after a forecast for stormy conditions heading into Friday morning.
And while another 14 millimetres of rainfall has turned the ground soft, the high-class card has been given the go-ahead.
Horse Racing Ireland tweeted: "Leopardstown to proceed today as planned, ground now soft following 14mm rain overnight.
"Forecast showers today with winds easing."
About 4,000 customers in Northern Ireland are without electricity after severe gales with gusts of up to 75 mph swept across the southern and eastern counties overnight. Trees fell across powerlines and electricity poles were broken and the Met Office weather warning for high winds and heavy rain remains in place until 7pm this evening, a Northern Ireland Electricity (NIE) statement said.
Emergency crews and engineers are assessing the damage caused and carry out repairs.
Julia Carson, communications manager, said, "We were in regular contact with the Met Office and had mobilised NIE emergency crews, engineers and call handlers in preparation for any damage the severe weather may cause. We have already restored power to 20,000 customers overnight and will continue to assess the damage and carry out repairs.
"As the weather conditions are set to continue there may be some areas where we will need to wait for the high winds to abate to allow our emergency crews to work safely."
A motorist dramatically escaped injury when a falling tree struck the car he was travelling in, as strong winds and heavy rain battered the country.
The motorist was travelling on the main Clonakilty to Bandon road in Cork last night, during the code-red weather alert, when the tree collapsed on to the car. He narrowly escaped without injury.
Meanwhile, in another incident, no one was hurt when a car overturned near Iniscarra, just outside Cork City.
The county was one of the worst hit as Met Eireann issued the code-red alert for the south and west -- its most severe weather warning -- which is expected to last until this afternoon.
Meanwhile, an amber alert is in effect in all other regions as almost 14,000 homes were last night without power as the strong winds damaged the ESB network.
Flights were diverted from all three main airports, Dublin, Cork and Shannon, as howling gales of up to 150kmh swept the country throughout the night.
Passengers on Aer Lingus and Ryanair flights bound for Dublin found themselves landing in Birmingham, Liverpool, Manchester and Glasgow
The high winds and heavy rain left many roads in the south and west of the country flooded and littered with the strewn debris from trees.
The stormy conditions caused damage to a canopy roof over one of the entrances to Cork University Hospital.
The incident didn't cause disruption to hospital services and maintenance staff were assessing the damage last night.
Other badly affected areas were Mayo, Galway, Clare, Kerry, Wexford and Waterford, with emergency services reporting "mayhem" on the roads, due to fallen trees and flooding.
There was severe flooding on the R617 road near Blarney in Cork, and motorists were urged to take care this morning with reports of dangerous road blockages caused by dozens of fallen trees.
AA Roadwatch was last night reporting fallen trees on roads near Nenagh, Co Tipperary; Ballinrobe, Co Mayo; Bettystown, Co Meath; New Ross and Enniscorthy, Co Wexford, on the N4at Riverstown Co Sligo and Mallow, Mitchelstown and Fermoy in Co Cork.
Gardai in Galway said there were dozens of trees down across the county causing multiple road closures and some road accidents but no injuries were reported by late last night.
Motorists were advised to take "extreme caution" as threacherous conditions were reported in Tralee, Ennis, Thurles and Clonmel.
In Castleconnell, Co Limerick, there were reports that a massive 100-year-old tree smashed into the car park of the SuperValu in the town.
The storm is expected to cease by evening.
More than 2,000 homes in Dundalk and Dunleer Co Louth sufffered power cuts and over 1,000 homes across Cork were also hit with the worst cuts occurring in the Rochestown and Douglas areas of Cork city, the Fermoy and Kilworth areas of north Cork and parts of Bandon.
ESB crews worked across Christmas to restore supplies after lightning cut electricity to large swathes of the country. A spokesperson said that further emergency crews were to be mobilsed from first light this morning to respond to the storm damage that occurred overnight.
In Dublin, Ballinteer Bridge was closed after the high winds downed power lines last night.
In all, almost 45,000 homes nationwide have been hit by power cuts since Christmas Eve.
The local coast guard unit in Dingle succeeded in carrying out a medivac mission yesterday at around 4pm after a woman, got into difficulty hiking on Mount Brandon, Co Kerry.
The woman, who suffered a suspected broken leg, was transferred to Tralee General Hospital by helicopter.
There were reports of a woman being swept into the sea at the docks in Galway.
Valencia coastguard said a call was received shortly after 10pm but an RNLI life boat dispatched to the scene was subsequently stood down and the woman, believed to be a foreign national, was said to be safe and well.
Public transport in Dublin was also disrupted with red line Luas services at Tallaght stopped last night due to an unsafe building beside the stop. The disruption is expected to continue until later today.
Conor Feehan, Emma Jane Hade, Clodagh Sheehy and Sam Griffin