A clean-up operation is underway after unseasonal storms, high winds and heavy rain led to power outages, damaged phone lines, flooding and disruption to a number of events and travel services.
The worst affected region was the west.
Heavy rain and winds of up to 120km per hour forced ferry sailings and other events to be cancelled.
Motorists have been warned to be careful of fallen trees.
AA Roadwatch is advising motorists to avoid driving unless absolutely necessary and to slow down, watch out for debris on the roads and take extreme care.
Bad weather also saw Irish Ferries cancel its 8.45am and 2.30pm Swift sailings from Dublin to Holyhead this morning.
All intending passengers were accommodated on the Irish Ferries Cruise Ferry at 8.55pm.
The HSS Stena Explorer from Dún Laoghaire to Holyhead at 11.10am has been cancelled.
All sailings of the Stena Express Fast Ferry from Rosslare to Fishguard have also been cancelled.
Passengers have been asked to contact Stena Line to make alternative travel arrangements.
Phones and electricity affected
Eircom says most of the affected phone lines in Cork, Mayo and Roscommon have now been reconnected.
Earlier up to 800 customers in Douglas, Co Cork, 200 homes in Glenamoy, Co Mayo and 300 homes in Roscommon were without a phone service due to weather related damage to the network.
Meanwhile, up to 2,500 houses in the Connemara Gaeltacht lost without power following a suspected lightning strike at an ESB substation overnight.
The damage was done to the station in An Cheathrú Rua and is effecting homes in the area.
Temporary power outages were also reported in Moycullen and Ballinasloe in Co Galway, but power has since been restored.
Galway was badly hit by the unseasonal storm.
Today's Corrandulla Agricultural Show was been cancelled because of the bad weather.
Following yesterday's flash floods, Galway City Council has under taken a clean-up operation.
Last night, a call centre for an out-of-hours GP service was forced to close after it was hit by flash flooding, but a spokesperson for Westdoc has confirmed that a partial service is in operation.
A Tesco store in the city was also forced to close for a time yesterday evening due to flooding
