Motorists have been advised to use caution after Met Éireann issued a weather alert following snowfalls in the north which left some roads in a dangerous condition.
Temperatures are expected fall to between zero and minus three degrees with a severe frost expected overnight.
Many schools were closed across Northern Ireland as heavy snowfalls led to difficult driving conditions. Gritting lorries were out in force earlier today.
Northern Ireland Road Service officials were urging drivers to proceed with extreme care on roads. Magherafelt, Cookstown, Craigavon and Dungannon were among the worst affected areas.
The Glenshane Pass on the road between Belfast and Derry was passable but motorists were being asked to take extreme care. Road Service workers were also working hard to ensure that motorways were still functional but were also urging caution.
Met Éireann has also issued a snow warning with showers predicted to affect many parts of the country, giving a covering of snow in some places but heavy snow showers were predicted at times in Ulster and North Connacht.
While the worst of the weather was experienced in Ulster, drivers faced treacherous conditions on their way to work in north Connaught as the snow moved southwards.
Motorists were warned away from some areas including the Sallygap in the Dublin mountains where cars were getting stuck due to bad ice and heavy snowfalls.
Sleet and snow over Munster and South Leinster are expected to clear southwards today and early tonight.