Motorists are also warned about plunging temperatures
There is a warning that flash flooding on many roads in the North East of the country can be expected tomorrow night.
Met Eireann has issued a status yellow rain warning which is in effect until Wednesday night at 11 pm.
Substantial rain is expected to fall in Cavan, Monaghan, Louth and Meath.
Meanwhile, motorists are being warned to take extra care, with dropping temperatures set to create icy road conditions tonight.
The Road Safety Authority is urging drivers to slow down and warns that black ice is likely in many areas.
It's also advising motorists to check vehicles for any damage that might have been caused by recent storms.
Brian Farrell from the RSA, says the cold weather follows weeks of rain: