The country-wide warning comes into effect at 10pm tomorrow night.
Met Éireann has issued a Status Yellow rain warning for country.
It's due to a band of heavy rain, which is expected to move nationwide tomorrow night and Monday morning.
The forecaster says the alert is valid between 10pm Sunday and 8am Monday morning.
It's also warning there could be thundery downpours, localised flooding, difficult travelling conditions and some poor visibility.
