Commuters may face challenging conditions as they return to work following the Christmas break, with temperatures set to drop as low as -4 overnight.
Met Éireann has said patches of freezing fog may develop overnight as the low temperatures combine with relatively calm conditions.
The coldest conditions are expected in the south of the country.
ROAD CONDITIONS: KILDARE: Black Ice remains on Athy/Kilcullen Rd.Icy at Wicklow county bounds on Blessington/Naas Rd https://t.co/9H7eVw9Wjc— AA Roadwatch (@aaroadwatch) January 2, 2017
The AA is also warning of black ice on some roads around the country, with motorists in Clare, Kildare and Wicklow advised to take care.
However, there is some good news as temperatures are expected to rise later in the week.