Motorists are being urged to take "extreme caution" as snow falls in parts of the country tonight.
Met Eireann earlier issued a Status Yellow rain warning for Carlow, Kildare, Kilkenny, Laois, Wicklow, Offaly and Tipperary until 2am on Thursday morning.
They said it may turn to "sleet and snow" in places, with snow falling Laois, Carlow, Kildare, Offaly and Wicklow so far.
Many roads nationwide are suffering from bad conditions, with the N80 getting some of the worst snowfall.
AA Roadwatch tweeted: "Extremely bad conditions on N80 between Tullamore and Portlaoise. Extreme caution is advised."
Weather chiefs also warned that the mercury will drop below freezing tonight, which could cause build-ups of snow and sleet to freeze in places.
However, it's expected that the snow to clear overnight and early tomorrow.
Talking about conditions this morning, a spokesman for the national forecaster said: "Generally cloudy with showers or longer spells of rain, light in northern areas but heavy at times elsewhere with a risk of hail and thunder.
"Top temperatures 5 to 8 degrees. Some of the rain will turn to sleet and snow in parts of Munster, Leinster and Connacht. Brisk northwest winds in the southwest today, but winds lighter and more variable elsewhere.
"The wintry mix of rain, sleet and snow will gradually clear southwards tonight.
"Cold clear spells will develop, with frost and some icy patches developing. Lowest temperatures of -1 to plus 3 degrees."
Thursday will be cold, dry and sunny for most of the day, with some showers affecting coastal counties in Leinster, Connacht and west Ulster.
It will be another bitterly cold night tomorrow, with temperatures again getting as low as -1 degrees.
