Met Éireann has issued a rainfall warning for Cork as well as Kerry, Galway and Mayo.
Between 25 to 40mm of rain is expected in the four counties between 6pm on Tuesday night and 12 noon on Wednesday.
Met Éireann is also warning that localised flooding is expected.
Last month's climate report from the meteorological service showed the majority of monthly rainfall totals for October were above their Long-Term Average (LTA).
Percentage of monthly rainfall values ranged from 80% (monthly rainfall total of 101.7 mm) at Sherkin Island, Co Cork to 158% (monthly rainfall total of 212.8 mm) at Markree, Co Sligo (its wettest October since 1998).
The number of rain days ranged from 21 days at Dublin Airport to 28 days at a few stations.
The number of wet days ranged from 15 days at Dublin Airport to 25 days at both Newport, Co Mayo and Markree, Co Sligo.
The number of very wet days ranged from 1 day at Roche’s Point, Co Cork to 8 days at both Newport, Co Mayo and Valentia Observatory, Co Kerry.