Met Éireann has issued a status yellow rain warning for Munster and Galway, alerting the public to a risk of spot flooding.
The warning, which comes into effect at 3am, will remain in place until 3pm tomorrow.
According to the national forecaster, spells of rain overnight and on Tuesday will be heavy at times leading to spot flooding.
The current outlook for Munster says that it will be a dry start in many areas tonight with light winds but that rain and drizzle will quickly spread from the southwest to all areas, while southerly winds increase fresh to strong and gusty.
Lowest temperatures will be around three or four degrees, turning "much milder" by dawn.
Tomorrow will be a dull, wet and windy day with outbreaks of rain and drizzle in fresh to strong southwesterly winds.
Rain will clear eastwards in the early evening with scattered showers following. Highest temperatures will range between 11 to 13 degrees.