Hail and snow storms battered parts of the north and west last night as forecasters warned of more snow and a sea storm for later in the week.
Met Eireann's snow-ice warning for Donegal, Leitrim, Mayo and Sligo was in effect until 10am today.
County council gritting lorries in Leitrim, Sligo and Donegal were out overnight on main routes as temperatures fell and Met Eireann issued a status 'Yellow' weather warning.
Dublin Fire Brigade reported a spate of road traffic collisions this morning in the icy conditions. While AA Roadwatch is warning drivers about the presence of black ice on roads.
Ice is lingering in a number of areas this morning and AA Roadwatch is advising motorists to slow down and to remember that gentle manoeuvres are the key to safe driving.
Heavy thundery showers will increasingly turn wintry today, especially over higher ground with some accumulations likely over hills.
Icing-like blankets of snow covered Errigal and Benbulben after snow falls yesterday afternoon, while bitter northern winds meant temperatures felt more like -5C for much of the day. Connacht, west Ulster, Kerry, Clare and Limerick got the brunt of the hail showers.
Met Eireann said that further wintry showers will likely continue today. Winds are set to pick up again tomorrow, with gusts of over 100kmph before stronger winds hit the west coast on Wednesday.
"Wednesday to Friday will be a very windy and cold period with passing wintry showers, and some accumulations of snow on hills in Connacht and Ulster, also higher parts of west Munster," said Peter O'Donnell, a forecaster with Irish Weather Online.
"People can expect some ice or snow problems especially overnight hours in higher parts of the north. Friday is now looking quite cold by afternoon and evening and this sharp cold will last for part of Saturday."
A huge Atlantic swell is expected on Wednesday, prompting excitement amongst surfers but a warning from the Irish Coast Guard with giant waves expected to bash the west coast.
"Thankfully it's a period of falling tides," said a Coast Guard spokesman.
"It will be tempting on the west coast to go look at the waves breaking at the evening high tide but we would ask people to exercise extreme caution.
"Unpredictable onshore breakers and darkness are a dangerous combination if you get caught out," he added.
Swell heights of up to 18m are expected at sea with waves in the region of 10m to 14m inshore.
Surfers are expected to congregate at Mullaghmore, Co Sligo, and Rossnowlagh, Co Donegal, on Wednesday to catch some of the waves.