Met Eireann has issued a snow warning for the entire country as temperatures plummet to -4C.
The caution will come into force from 11pm on Wednesday night, expiring at 11am on Thursday morning.
Meanwhile, a second alert for low temperatures and ice was also released, with a big freeze set to hit the whole country between 8pm and 10am.
A forecaster said: "Snow and ice will lead to treacherous conditions. Some accumulations possible. "
And Met Eireann has predicted another perishing set of conditions over the next few days, with ice and sleet in for the long haul.
Icy patches are likely to form on untreated surfaces, and motorists are still being urged to be extremely careful on the roads after a number of crashes this week.
Meanwhile, Friday is due to bring "bitterly" cold conditions ahead of a weekend that could see a very slight uptick in temperatures.
Met Eireann's forecast for today reads: "Very cold this morning, frost and ice will linger in some parts throughout the day.
"Wintry showers in Leinster will become mainly confined to the coast during the afternoon, elsewhere it will remain dry with some sunny spells.
"Cloud will increase from the north and west during the afternoon, preceding a band of rain or sleet arriving during the evening. Highs of just 0 to 4 degrees in light variable breezes."
