Met Eireann has issued a status yellow rainfall warning for Connacht, Longford, Louth, Westmeath, Meath, Cavan and Monaghan.
The warning was issued at 4pm on Sunday and it's in place from 9pm on Monday, January 18 until the same time on Tuesday, January 19.
The warning states: "Heavy rainfall will lead to accumulations of 30 to 50mm, with higher accumulations in mountainous areas. This will bring a risk of some river and localised flooding.
In terms of the general weather forecast for the next few days, tonight is set to be largely cloudy with outbreaks of rain and drizzle, persistent at times across Ulster.
Tonight will bring further patchy rain, drizzle and mist. There will be clear spells too, but cloud will thicken in the southwest later in the night.
Lowest temperatures are set to range between 0 to 4 degrees, with frost developing in some places.
As for Monday morning, sunny spells in the north and east are expected, but it's set to become overcast and misty as the day goes on with scattered outbreaks of rain and drizzle.
Conditions are set to become unsettled and turning colder with some wintry falls possible. Rain will become more widespread during the evening too, with a wet and misty night with some heavy falls of rain expected.
