Flood warning issued over rain
Motorists have been warned to take extra care as heavy rainfall is expected to flood roads.
Between 30mm and 50mm of rain are forecast to fall along the east and south east coast, with high tides due to add to problems.
Met Eireann said heavy rain will move across the country, with intense rainfall during short periods leading to local flooding.
There will also some heavy, prolonged and local thundery showers during the day.
"Southern and eastern coastal counties will have the heaviest of the rain with accumulations of between 30mm and 50mm forecast, with values possibly higher in mountainous areas," Met Eireann said.
"But coastal areas of the south and east have the added threat of coastal flooding due to a combination of spring tides, high seas, occasional onshore gales and low pressure values."
Dublin City Council warned there will be three high tides during the weather alert.
Flood gates on the River Dodder have already been closed, car parks at Sandymount and Clontarf are closed, and the Liffey Boardwalk defences will be closed during Wednesday morning.
Flood defences on the River Tolka are also being put in place.
"There may be very localised wave overtopping in parts of Sandymount and Clontarf," it added.