Status yellow rain warnings have been issued for counties Cork and Waterford for Sunday evening, with Met Éireann warning of heavy and persistent rain that could lead to spot flooding.
A rain warning will come into effect for Cork from 5pm on Sunday and will remain in place until 11pm that evening.
A yellow warning will also come into effect in Waterford from 8pm on Sunday due to heavy rain forecast for the county. It will remain in place until 2am.
It comes as temperatures tonight could drop as low as freezing, with Met Éireann forecasting a milder turn in the weather over the coming days.
The weekend will start off with some showers in the north and west in the country that could turn heavy as they track eastwards, though these will clear by early afternoon.
Sunshine and scattered showers will follow, with conditions becoming largely dry by this evening as temperatures reach highs of 9 to 13 degrees throughout the day.
It will be a chilly, dry night as temperatures are expected to drop to lows between zero and 5 degrees.
Sunday will see hazy, sunny spells before they are broken by some patchy rain and drizzle which will turn more persistent with chances of localised flooding in the southwest.
Rain will extend northeastwards by nightfall, bringing heavy rain in places as temperatures hit highs of 7 to 10 degrees over the north of the country and 10 to 14 degrees further south.
Overnight temperatures are expected to reach lows of 3 to 7 degrees, with Met Éireann warning of heavy rain and localised flooding on Sunday night.
Monday will see a mix of cloud, sunny spells and isolated showers with highs of 11 to 16 degrees while overnight conditions will bring some drizzle and hit lows of 6 to 11 degrees.
Met Éireann forecasts further cloud and sunny spells with scattered outbreaks of drizzle with highs of 14 to 17 degrees, increasing slightly to highs of 15 to 18 degrees on Wednesday when sunny spells are expected.
The outlook for the days following currently shows generally unsettled conditions with spells of rain and showers, Met Éireann has said.