Carlow has been included in a Status Yellow rainfall as Met Éireann has issued a warning for Munster and Leinster.
The national forecaster says heavy rain will spread from the south Thursday evening and night.
Accumulations of 25 to 40mm will occur over a relatively short time period.
Spot flooding is likely.
The warning is valid from Thursday, August 8 at 7pm to Friday, August 9 at 7am.