So this is spring? It looked more like deepest winter as commuters and schoolchildren woke up today to a blanket of snow in many parts.
And Met Eireann has issued a special weather warning to more than a dozen counties.
The severe weather caused numerous traffic accidents, with a lorry jackknifing 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.
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.
Tonight there will be some isolated snow showers and it will remain cold, with widespread severe frost and lowest temperatures of -1C to -4C.
AA Roadwatch reported heavy snow this morning falling on the M1 at Donabate and on the M50 between the Ballymun and Blanchardstown exits.
Snow was reported in suburbs across the capital, particularly Swords, Malahide and other areas in north Dublin.
Gardai warned motorists to take care around Balbriggan as snow continued to fall. Temperatures fell to as low as -5.2°C in Donegal last night while snow and ice in the Dundalk area caused several traffic accidents.
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 let-up, with northerly winds and slightly higher temperatures of 6 or 7 degrees – but with a severe frost during the night.