Cold, frosty and snowy weather is expected to continue throughout the weekend.
Met Éireann has issued a severe weather warning predicting widespread snow showers for this evening, tomorrow and Sunday.
A spokesman said the the east coast would see much of the snow showers tomorrow after the north of the country bore much of the brunt today. The strong northerly winds battering the country will ease overnight and into tomorrow although it will remain very cold into early next week.
AA Roadwatch has advised motorists to plan journeys carefully and to take "extreme care" over the next few days.
Most main routes have been treated, although motorists should watch out for black ice, particularly on secondary roads. Conditions are bad in the north and west, particularly in Co Donegal and higher ground in Wicklow. The Sally Gap is impassable due to snow and dangerous driving conditions.
Most ferry crossings have been cancelled. Two Aer Lingus flights to Rome have been delayed due to a general strike in Italy. The 7.10am flight to Rome departed at 1pm and a flight from Rome to Dublin due to land at 14.30 will now land at 20.10.
Sports fans willing to brave the weather can take in the Dublin City v Shamrock Rovers relegation battle at Tolka Park at 8.05pm tonight.
Ireland take on Romania at Lansdowne Road tomorrow at 12.30pm in the last game of the autumn international rugby series. Heavy traffic is expected in the Ballsbridge area.
Racing is at Gowran Park tomorrow, with the first race under way at 12.50pm, and the last race on the card due to go off at 3.50pm. Sunday racing takes place at Wexford and Navan. First race at Wexford is 12.30pm, and 12.40pm at Navan. All meetings are subject to morning inspections due to poor weather conditions.