More than 6-and-a-half thousand homes and businesses are without power this morning, after winds of up to 100 kilometres an hour overnight.
Most of the affected customers are in Blessington in Co Wicklow, and Enniscorthy, Co Wexford - and two thousand homes are off the grid across Munster.
The ESB says crews are working to restore service as quickly as possible.
Motorists are warned to take care for debris on the roads - while Irish Rail says DART and commuter services have been suspended north of Connolly Station in Dublin because of a fallen tree.
Irish Rail spokesperson Barry Kenny says services won't resume for some time.
