Motorists have been advised to drive with extra care overnight and especially tomorrow morning after a very hard frost is falling over country tonight.
Experts say snow is possible as temperatures took a nosedive at teatime on Wednesday.
Met Eireann have advised that black ice will still be on the roads this morning with the AA advising people drive slower than usual after temperatures dropped to -3c.
From 10pm onward on Wednesday night, a frost fell, especially on the east coast with temperatures dipping below freezing in many places.
This week will be considerably colder than last week with daytime temperatures only rising to around 6c with nighttime temperatures going before zero.
People are advised to share this information with their friends.