Stormy conditions have disrupted power supplies and phone services in many parts of the country.
Driving conditions were also hazardous on many roads this morning.
Eircom says up to 8,500 customers are without phone lines because of damage to its network from strong gales and heavy rain overnight.
The worst affected areas were the northwest, southwest Connaught and the Carlow, Kilkenny and Tipperary regions.
Eircom's Storm Recovery plan is in place. While crews are working to restore services as soon as possible, that could be next week for some customers.
The ESB has so far restored power to about 6,000 customers affected by last night's storm. However up to 12,000 customers nationwide, about 10,000 of whom are in Co Donegal, are still without electricity.
Crews have been drafted in from other counties to help re-connect power in Donegal where Inishowen, Fanad and Gweedore are the worst affected areas.
An ESB spokesman said it would now be this evening before all the customers will have power restored.
Around 3,500 homes in Northern Ireland were also left without electricity.
Conditions were bad on many of the country's roads this morning, with reports of snow, black ice, strong winds, debris & flooding.
The 7.40am and 11am Stena Line HSS sailing from Belfast to Stranraer in Scotland were also cancelled due to the bad weather.
