A Status Yellow weather warning has been issued for Cavan and Monaghan.
The rain warning will come into effect at 11pm tonight and remain in place until 11pm tomorrow.
Met Eireann is warning rain falling on already saturated ground combined with high river levels will lead to, flooding, poor visibility and difficult travelling conditions.
Leinster, Cork, Tipperary and Waterford will also be impacted.
Meanwhile, a Status Yellow Wind warning is issued for Wexford, Wicklow, Dublin, Meath and Louth.