Drivers are being asked to take extra care on the roads as the cold snap bites.
Thursday will see an icy start with black ice and patches of freezing fog leading to hazardous travel conditions.
Scattered showers will also continue to sink southwards, turning wintry in parts with a light dusting of snow on some lower levels.
Sunny spells will follow, as wintry showers become confined to northern coastal counties.
However, after-dark showers of sleet and snow will move into parts of the east.
Treacherous this morning with ice & black ice, as well as pockets of freezing fog. ⚠️ 🌫️
Scattered wintry showers will sink southwards with sunny spells following. 🌨️
Very cold with highs of 1 to 5°C in mostly light northerly breezes. 🍃 pic.twitter.com/IgqXLIeH3j
— Met Éireann (@MetEireann) December 8, 2022
Thursday will see highest temperatures of just 1 to 5° in light northerly or variable breezes.
Tonight will again see treacherous conditions, with a severe frost setting in quickly after-dark along with some icy stretches.
There will be some wintry showers of sleet and snow - mainly across east Leinster - with some lying snow possible.
Met Éireann has said it will be "bitterly cold" on Thursday night, with lowest temperatures of -5 to -2° in a light northerly breeze.
There will also be some freezing fog developing.
It comes as several weather warnings remain in place for the entire country.
A Status Yellow ice and low temperature warning have been issued into today and Friday, respectively.