Met Éireann has issued a status yellow snow and ice warning for Donegal.
The warning will come into effect at 3pm on Wednesday and will remain in place until Thursday at 8am.
Met Éireann has said: "Showers will turn increasingly wintry during Wednesday with a mix of hail, sleet and snow, leading to icy conditions on untreated surfaces.
"Some localised accumulations will occur."
The rest of the country is set to see a "blustery and showery day" on Wednesday.
The forecaster has predicted "some sunshine but also widespread showers merging to give longer spells of rain during the afternoon."
They added some of the showers will fall as hail and "will turn increasingly wintry with snow on high ground by evening, particularly in west Ulster."
Met Éireann said the weather looks likely to remain unsettled as the week continues.
Thursday is set to be cold and windy with "sunny spells and widespread showers and longer spells of rain at times."