Met Éireann has issued a Status Yellow rainfall warning for two counties, which is due to come into effect at 10:00a.m tomorrow morning (Saturday, July 19).
The national forecaster said that there is a risk of heavy rain in counties Kerry and Cork, paired with possible isolated thunderstorms.
The weather warning will remain in place until 10:00a.m Sunday morning (July 20).
The conditions will bring a risk of spot flooding, poor visibility, and difficult travelling conditions.
Some areas are predicted to receive up to 30mm of rain throughout the period covered by the warning.
Meanwhile, Met Éireann has forecasted unsettled weather for the rest of the country over the weekend, with frequent showers promised.
Cloud cover will remain present throughout today (Friday, 18 July) with isolated spells of rain.
The evening is set to brighten up with high temperatures between 17° and 21° paired with moderate south-west winds.
Tonight will remain cloudy and moderately dry, with showers in places before the southwest rain advances in the morning.
Tonight's temperatures will reach a low of between 10° and 14° as light westerly or variable breezes, becoming south-easterly by morning.
Tomorrow's (Saturday, July 19) rain will advance over counties Cork and Kerry in the morning, with heaviest showers expected in the evening.
The rain will make its way across the rest of Munster in the afternoon and throughout the night and early morning.
Most of Munster and parts of Leinster and south Connacht will experience heavy showers.
Met Éireann are warning these areas are also at risk of spot flooding, while northern areas will remain relatively dry throughout Saturday, with rain in places on Sunday morning
Highest temperatures tomorrow will be 16° to 21°, coolest in the south-west, with moderate, occasionally fresh south-easterly winds developing, strong at times on southern coasts.
Lowest temperatures are expected to be 10° to 15° paired with moderate cyclonic variable winds.
Sunday (July 20) will see a mix of sunny weather with showers or showery outbreaks of rain, heavy at times with possible thunderstorms, especially in the north. It will be driest generally in southern areas.