It will remain very cold on Wednesday with frost, icy stretches and the potential for patches of fog or freezing fog.
The Met Office has issued a yellow warning for snow and ice for the whole of the north following sleet and snowfall on Tuesday.
It has warned the public to be wary of icy patches on some untreated roads, pavements and cycle paths and the potential for some injuries from slips and falls on icy surfaces.
Met Éireann has forecast that fog will clear very slowly but will linger in some areas all day.
Temperatures of just 0 to 3 degrees are forecast with scattered wintry showers in northern counties and some snow flurries.
Wednesday night will be very cold with some wintry showers, mainly in the north and west, with lowest temperatures of -4 to -1 degrees with light northwest breezes.
