Met Éireann has issued a status yellow rain warning for Galway which will come into effect on Saturday night.
The forecasters have said that high amounts of rainfall from Saturday night until Sunday morning may cause disruption.
The warning for all counties in the Republic will begin at 9pm on Saturday and is expected to be lifted at midday on Sunday.
As for today, more persistent rain will develop in the west in the afternoon, gradually spreading eastwards over Connacht.
Met Éireann has forecasted high temperatures of between 17 and 21 degrees in moderate breezes, varying in direction.
Some heavy rainfall is also expected tonight and tomorrow afternoon, with some heavy and thundery showers possible.