Met Éireann is warning of localised flooding in parts of the south and west on Thursday.
A status yellow rain warning has been issued for Cork and Kerry from 11:00am until 5:00am on Friday.
Persistent and at times heavy rain is forecast.
This will lead to localised flooding, with the highest accumulations expected in the mountains.
While a separate status yellow rain warning is in place for Galway and Mayo from 5.00pm Thursday.
The alert, which runs until 1.00am on Friday, will see heavy rain over a relatively short period of time.
Met Éireann says this may lead to localised flooding - with the highest accumulations expected in the west of these counties.
Heavy rain over a relatively short period of time may lead to localised flooding. Highest accumulations expected in the west of these counties.
Regions: Galway and Mayo
Expected Onset: Thursday 30/12/2021 17:00
Expires: Friday 31/12/2021 01:00 pic.twitter.com/7qZcRakoUo
— Met Éireann (@MetEireann) December 29, 2021
It comes following 'extensive' flood damage in parts of Co Wexford over the Christmas period.
The town of Enniscorthy saw several bridges and roads destroyed.
Wexford TD Verona Murphy says it's time to find the "political will" to get a flood relief scheme for the town.
She told The Hard Shoulder on Wednesday the cost of the scheme has only increased since it was put forward back in 2012.
She said: "The reality is it goes back to 2012… the Office of Public Works told [councillors] what would be required. Enniscorthy had major tidal issues, and climate change would affect any flooding in the town.
"Back in 2012, they estimated the cost to be €66 million if they didn’t do anything, while the scheme itself would cost in the region of €25-40 million… today the estimated cost of damage is in the region of €100 million for not doing anything. We can see that now, as we have several bridges collapsed in the county."
Deputy Murphy added she believed the planning process is being used as "an excuse" for further delays.
She said: "I believe where there is a will, there is a way - we need to find the political will to get this scheme underway."