Some 12,000 and 13,000 ESB customers remain without power, ESB Networks has said.
Wind and rain hampered the restoration process earlier today, it said.
"The additional rain and wind last night makes the task more difficult as access to fix the network continues to be very difficult."
Since Hurricane Darwin crews have been working "from dawn to dusk" and they have restored supply to over 260,000 homes and businesses, the company said.
Over the past four days, from Thursday to Sunday, ESB has replaced approximately 1,700 poles, 400 kilometres of conductor and 400 transformers.
ESB Networks has warned people against handling cables. A number of "worrying" incidents have happened already, he said.
"Technicians have observed a number of extremely dangerous and worrying incidents where members of the public have put themselves in danger by rolling up broken conductor and either placing it at the bottom of a pole or taking putting it in a nearby ditch."
"Some of our lines have are coated in PVC but are not insulated," an ESB statement warned.
Customers using generators should also observe the safety precautions and ensure they do not connect a generator to a socket or distribution board.
Doing so will create a feed onto the electricity network and will pose a danger to others including repair crews.
ESB Networks has over 5000 faults still to address.
The areas with the most customers remaining without power are the surrounding areas of: Tralee, Dunmanway, Killarney, Fermoy, Newcastlewest, Tipperary and Enniscorthy.
Customers without power can check for updates on when their fault is expected to be repaired at: www.esbpowercheck.ie, via Twitter at @ESBNetworks or telephone 1850 372 999 and have their MPRN available to access recorded information specific to their location.
Following Storm Darwin, over 8,000 faults have been recorded across the electricity network.