A status yellow low-temperature warning has been issued for the entire country.
Met Eireann is warning of hazardous conditions as temperatures are set to fall to -4 degrees.
A sharp to severe frost with icy surfaces and some freezing fog patches are forecast.
The warning will come into effect from 10pm tonight and remain in place until 12pm tomorrow.
A sleet and snow warning has been issued for Donegal.
The status-yellow warning comes into effect tonight at 9pm until 12pm on Saturday.
Met Eireann says scattered sleet and snow showers will give some accumulations, especially on high ground.