Met Éireann is warning of significant snowfalls across parts of the country over the next 24 hours.
Forecasters say a band of rain and sleet will move up from Munster tonight and fall as heavy snow over Leinster, Connacht and the Midlands overnight.
Combined with strong easterly winds, it will make for very unpleasant outdoor conditions.
Up to 6cm of snow could accumulate on the ground, and maybe up to 10cm in parts of the north Midlands and Ulster.
Farmers in some areas are being advised they may want to bring animals indoors.
Local authorities are making arrangements to clear and grit roads.
The Road Safety Authority has said unnecessary journeys should be avoided and special care is needed by those who are due to travel.
It comes after road temperatures reached -7C in parts of the country this morning, leaving driving conditions hazardous.
This morning motorists were being warned about hazardous driving conditions across the country.
Counties Wexford, Wicklow, Kilkenny, Cavan, Monaghan, and Dublin and its hinterland had all been identified as dangerous.
