The ESB is reporting power outages in Dublin, Wicklow, Wexford and Waterford.
The power company is working to fix several lightning-related faults.
A yellow weather warning remains in place, as overnight thundery rain in the south pushes northwards this morning.
There is a risk of local flooding and hail in some parts, with Munster and Leinster seeing the heaviest of the rain.
Driving conditions are treacherous in the areas affected.
Ruth Jephson of AA Roadwatch has this advice:
Met Éireann says there's a risk of local flooding this morning caused by thundery rain.
Thundery rain pushing N causing treacherous conditions.Though the day will improve still some heavy showers later.Warm & close.Highs 19-23C
— Met Éireann (@MetEireann) July 18, 2014
However if you have weekend plans, such as music festival Longitude - conditions will improve later.
Meteorologist Siobhan Ryan says it won't be a complete washout:
