Met Eireann has issued a snow and ice warning for eight counties and a wind warning for parts of the country.
Longford, Cavan, Managhan, Donegal, Louth, Leitrim, Roscommon and Sligo are all at risk of snow and ice tonight, with wintry showers expected.
The warning is in place until 7am tomorrow morning, Monday, December 28.
The UK Met Office has also issued a Yellow Snow and Ice Warning for Antrim, Armagh, Down, Fermanagh, Tyrone, Derry.
There is also a Status Yellow Wind Warning for Donegal, Galway, Mayo, Sligo, Clare, Cork and Kerry
Met Eireann is warning that northwesterly winds associated with Storm Bella (named by the UK Met Office), veering northerly overnight, will reach mean speeds of 50 to 65km/h with gusts of 90 to 110km/h. Winds will be stronger in exposed areas and on higher ground.
With the combination of strong winds, high waves and forecasted storm surge, there is a risk of coastal flooding.
The warning is in place until 2pm on Monday.