Met Éireann has issued a Status Yellow rainfall warning for Waterford.
Carlow, Kilkenny, Wexford and Wicklow are also included in the warning from the national forecaster.
The forecaster is predicting heavy rain overnight with 20-30mm expected across the South East.
The warning is valid from Sunday, November 4 at 9pm to 9am on Monday, November 5.
Motorists are being advised to exercise caution on the roads.