Snow and blizzards caused Met Eireann to issue a weather warning today for more than 12 counties.
The severe weather caused numerous traffic accidents, with a lorry jack-knifing in Louth and gardai reporting 10 weather related crashes on the Dublin-Sligo route.
Irish Ferries cancelled all Swift vessel sailings on the Irish Sea while Stena Line cancelled its Rosslare-Fishguard sailing.
At Dublin Airport, workers were carrying out sweeps of runways with officials reporting minimal disruption.
A spokesperson for the airport said some flights had been diverted whilst others were experiencing delays.
Passengers are advised to consult the airline’s website to check on their travel plans.
Some of the worst weather hit north Dublin and Louth.
Met Eireann forecaster John Eagleton said temperatures are “way below normal” for March, with strong north easterly winds adding to the chill factor.
Temperatures were not expected to rise above 3C today as the chill continues.
Forecaster Vincent O'Shea says that the extremely cold weather will linger until Thursday at the earliest.
"We are in an unseasonable cold snap. Ice and frost are going to be the main feature but sleet and snow are highly likely in many areas," he said.
"The Dublin area is going to be quite badly hit, not right beside the coast but inland and in higher areas."
As much as 10cms of snow could fall in the Wicklow mountains, with a more modest 3cms expected in west Dublin. Wexford and Waterford are also in for tough weather conditions in the coming days.
Gardaí were dealing with around ten separate crashes on the M4 Dublin to Sligo road between Enfield and Leixlip.
AA Roadwatch reported treacherous roads around the Dundalk area.
Tomorrow is expected to be mainly dry and bright but still cold, with highs of 4C to 5C with moderate northerly winds.
Wednesday will see no letup, with northerly winds and slightly higher temperatures of 6 or 7 degrees – but with a
severe frost during the night.