Weather forecasters have warned that further showers of snow today may see up to five centimetres fall in many parts of the country.
Met Éireann said up to 10 centimetres of snow may fall on high ground after temperatures plunged last night and snow showers made many roads treacherous.
Road conditions were particularly bad this morning in the west, north west, the midlands and south of the country. There have been a number of crashes, and motorists have been told to avoid the Sally Gap in Wicklow.
AA Roadwatch also reported that conditions were particularly bad this morning on the N80 between Portlaoise and Stradbally, in Kerry on the N69 around Listellick and on the N8 at Thurles.
Wintry showers will become confined mainly to northern and eastern coastal areas tonight, but a sharp to severe frost will develop everywhere.