While the east of the country is seeing the most severe weather today, a status yellow snow & ice warning has been issued for Connacht, Munster and Leinster for this Thursday.
Met Eireann says a band of sleet and snow spreading northeastwards during Thursday will give snow accumulations of up to 5 cm in some areas - higher over mountains.
The 24-hour warning comes into effect from 8am Thursday morning.
Meanwhile, a status yellow snow and ice warning is in place for 5 counties today.
The alert for Louth, Westmeath, Meath, Cavan and Monaghan is in place until 6 tomorrow evening.
In this region, tonight will be bitterly cold with a widespread frost, and temperatures dropping as low as minus 5 degrees with icy stretches forming.
AA Roadwatch is advising motorists driving in slippery conditions to stay well back from the vehicle in front, as it can take up to 10 times longer to stop in snow and ice.