A status yellow rainfall warning has been issued by Met Éireann for Munster, Dublin, Carlow, Kildare, Kilkenny, Laois, Longford, Wexford, Wicklow, Offaly, Westmeath, Meath, Galway and Roscommon.
Bands of heavy thunderstorms are to move up from the southeast on Sunday morning, giving torrential downpours locally in short periods leading to spot flooding.
Met Éireann has said there is also a risk of hail.
The warning is in place until 12:00pm.