Met Éireann has issued Status Yellow rain warnings for a number of counties in the coming days.
A warning is in place for six counties from 2:00p.m on Friday (September 19) until midnight.
The counties affected are: Carlow; Cork; Kilkenny; Waterford; Wexford; and Wicklow.
A 24-hour Status Yellow rain warning is also in place from midnight on Saturday night (September 20).
This warning is in place for the following counties: Carlow; Cork; Dublin; Kildare; Kilkenny; Laois; Louth; Meath; Offaly; Tipperary; Waterford; Westmeath; Wexford; and Wicklow.
Met Éireann said there will be spells of heavy rain at times, heaviest in the east and south east.
Possible impacts include localised flooding, poor visibility and difficult travelling conditions.
The UK Met Office has also issued a Status Yellow rain warning for counties Antrim and Down, in place from 12:00p.m Saturday until 3:00a.m Sunday.
There is a small chance that heavy rain may lead to flooding and travel disruption.
Today (Thursday), there is rain and drizzle in all areas, which is expected to become light and patchy this evening, Met Éireann has forecasted.
Tonight will be mostly cloudy with outbreaks of rain, mainly in Munster, Leinster and east Ulster.
Rain will be heaviest and most persistent in the south-east. Some western and northern areas will be mainly dry, and some hill and coastal fog is expected too.
On Friday morning, rain, drizzle, mist and fog will mostly clear eastwards but will linger in the south-east.
It will become mainly dry with some bright or sunny spells extending from the west, but staying mostly cloudy in the east and south-east.