A Status Yellow rain warning is in effect for three counties, with Met Éireann saying there will be spells of heavy rain.
The warning for counties Cork, Kerry and Waterford came into effect at 9am and will be in place until 6am tomorrow.
The forecaster said there may be spot flooding, poor visibility and difficult driving conditions.
Met Éireann said there would be outbreaks of rain and drizzle across the western half of the country today, spreading eastwards this evening.
Rain and drizzle will spread nationwide tonight with some heavy falls in the south.
