A status yellow rainfall warning is in place for 18 counties including Waterford.
It came into effect at 11pm last night and will be in place until 11.59pm tonight.
The counties included in the warning include all of Munster and Connacht, as well as Carlow, Kilkenny, Laois, Longford, Wexford, Offaly and Westmeath.
Met Éireann said: "Heavy rainfall expected during the period with some heavy bursts occurring in short intervals of time.
"There is potential for flooding."
They added that there would be "persistent rain in many areas" and "also a risk of some thunder".
The forecaster added that tomorrow there will be some sunny spells.
They said it will be "largely dry across the country, however wet and windy weather will move into the west and southwest by early afternoon."
