Met Éireann has warned that frequent heavy showers on Saturday in Donegal, Leitrim and Sligo may lead to localised flooding this weekend.
For the second weekend in a row a yellow rain warning has been issued for the northwest, and will be valid from 9am on Saturday morning until midnight.
Last week, flash flooding caused severe disruptions in the town of Raphoe in Co Donegal.
Rain is expected to spread across the country on Saturday and into Sunday – especially during the afternoon when Dublin take on Kerry at the All-Ireland football final at Croke Park.
Further outbreaks of rain are expected with more unsettled weather into next week, according to Met Éireann.
Showery rain is expected in the north and west on Friday, with highest temperatures of 16 to 21 degrees nationwide, warmest towards the east and with moderate southwest winds.
Tonight, temperatures will be between 11 to 13 degrees, and scattered showers mixed with clear spells are expected.
On Saturday, scattered showers and sunny spells are forecast to continue throughout the day. Some of the showers are predicted to be heavy and possibly thundery in the north west.
The best of the dry intervals are expected in Leinster, however nationwide it is expected to be quite breezy with moderate to fresh southerwesterly winds, and highest temperatures of 16 to 20 degrees warmest towards the southeast.
Scattered showers will continue overnight on Saturday, remaining heaviest in the north west with drier intervals elsewhere in the country, and temperatures are not expected to rise above 14 degrees.
Sunday morning is expected to start cloudy but dry, with a few showers continuing mainly in Ulster.
Persistent outbreaks of rain will descend across the country from the west throughout the afternoon and evening from midday on Sunday, with maximum temperatures of 16 to 20 degrees in mainly moderate west to southwest winds.
These outbreaks of rain will continue throughout Sunday night, which Met Éireann predict will be quite humid with lowest temperatures of 14 to 16 degrees in light to moderate southwesterly breezes.
