Pedestrians and road users are being urged to take care in icy conditions with temperatures hovering around zero in many parts of the country.
Temperatures are forecast to remain low with sleet and hill snow expected to fall, particularly in parts of the north.
In the midlands, a thaw is under way with county councils reporting that all local and regional roads are now passable and gritting of housing estates and footpaths is continuing.
Roscommon and Westmeath county councils are hoping to clear more footpaths today after residents in some estates complained they have been unable to get out of their homes due to dangerous underfoot conditions.
The majority of primary and secondary schools in the midlands reopened today.
Yesterday, homeless charities said they were making extra efforts to ensure that anyone who needed a bed overnight would have one.
Community groups in rural areas have appealed to residents to look out for older neighbours, in particular those who live alone.
Britain had its coldest night of the year as vast swathes of the country fell below freezing, with -13C recorded in Shropshire.