A status yellow rain warning has been issued for Cork by Met Éireann.
The national forecaster is predicting heavy spells of persistent rain which will lead to localised flooding.
The weather warning is valid from 3am Wednesday to 3am Thursday.
On Thursday, Met Eireann is expecting further showers or spells of rain but sunny spells will break through later in the morning and for the early afternoon.
Highest temperatures will be 12 to 15 degrees in light to moderate south to southwest breezes.