Icy road conditions have been widely reported across north Leinster, parts of the midlands and counties Mayo and Roscommon.
Within the last hour AA has advised motorists to be particularly careful in north Meath where black ice has been reported in Trim, Warrenstown and around Bettystown.
Icy conditions have also been reported in Wexford on the Arklow/Gorey road (Old N11/R772).
In Connacht, there are extremely icy conditions across Roscommon and Mayo, particularly on the M4.
Ice has also been reported on the N4 Dublin to Sligo road at Ballinalack, the Drumsna and Jamestown turn-offs, Carrick-on Shannon, Boyle and Collooney.
In Co Cavan very icy conditions have been reported on the N87 Belturbet/Ballyconnell road, while motorists should also also be aware of fog around Cavan town.
Frost has also been reported on the Nangor road at Grangecastle. Extremely icy conditions have been reported on the old N2 (R135) between Ashbourne and The Ward Cross in counties Meath and Dublin.
In Co Louth, motorists have reported icy conditions at the Bridge of Peace in Drogheda and on minor roads around Dundalk
Icy conditions have been reported on the Abbeyleix to Carlow and the Abbeyleix to Stradbally roads in Co Laois.
Met Éireann has forecast cold and windy weather today with occasional sunshine and showers. The showers will be most frequent across the western half of the country while highest temperatures should reach five to degrees.