Met Éireann has upgraded a snow and ice warning to 'status orange' tonight.
The weather forecaster predicting wintry, thundery showers of hail, sleet and snow along with icy patches - from the early hours of Tuesday - with possible snow accumulations of 4 to 8 centimetres.
The alert is in place for Connacht, Cavan, Monaghan, Donegal, Clare, Kerry and Limerick
Meanwhile, a status yellow alert is also in place for Leinster, Cork, Tipperary and Waterford -with wintry showers of hail, sleet and snow expected.
"Icy patches will form in any locations escaping snow showers," the warning states.
"Further thundery snow showers and similar accumulations will occur during the day on Tuesday and on Tuesday night."
Joanna Donnelley is a meterologist with Met Éireann
The Status Yellow alert is in place for Connacht, Cavan, Monaghan, Donegal, Clare, Cork, Kerry, Limerick and Tipperary.
Temperatures are also expected to drop below freezing in Leinster, Monaghan and Waterford.
WIndy with shwry rain & sleet in W this eve spreading E tonight. Rain will clear and there'll be wintry shwrs in the W tonight, with.....— Met Éireann (@MetEireann) January 12, 2015
...accumulations of snow overnight & tmrw. Lows between -2 to +2 deg.— Met Éireann (@MetEireann) January 12, 2015
"Over the next 24 hours or so, we're going to see some accumulations, mostly affecting western coastal counties, of snow," said Met Éireann meteorologist Joanna Donnelley.
"Elsewhere, where it's not snowing, it'll be cold, icy on the roads where they are not treated, and basically hazardous driving conditions everywhere for a little while anyway."
The warning remains in place until 8am on Wednesday.
There are also two Status Yellow marine warnings in place, warning of Southwest winds reaching gale force at times this evening and tonight on coasts from Valentia to Erris Head to Fair Head.
Winds are expected to reach force 6 or 7 on coasts from Fair Head to Carnsore Point to Valentia.