Gale-force winds have caused overnight power cuts across the country leaving thousands of homes without electricity.
Crews worked through the night to restore services, but some 1,500 customers were still affected this morning.
A spokesman for the ESB said fallen trees and branches had caused many of the faults.
Motorists have also been warned to take extra care while driving as debris caused by strong winds has left some roads blocked.
AA Roadwatch said conditions were particularly bad in the north-west.
Fallen trees were reported across Cavan, Longford, Roscommon, Mayo and Donegal.
Meanwhile, Met Eireann was forced to issue a weather warning to small sea craft early this morning with south-west to west winds reaching force six on coasts from Howth Head to Roche’s Point to Erris Head on the east coast.
Good morning #Ireland. Nice day after all the wind and rain of last night.
— We Love Ireland (@FollowIreland) December 23, 2012
Gusts hitting 70mph had an impact across the eastern part of the North, with several roads barred by fallen trees.
Holywood Road in Belfast at the Harland and Wolff football ground is closed, as is Circular Road.
One lane of Main Street in Kircubbin, Co Down, is also closed. Several smaller roads have also been closed.
About 50 homes in Downpatrick are without electricity because of the wind.
Power NI said the electricity network has coped well with the weather.