Temperatures are due to drop to as low as minus four degrees on Monday and Tuesday night, with Met Éireann issuing a cold weather warning for the entire country.
The national forecaster has warned motorists the roads could be dangerous on Monday morning due to patches of ice.
A nationwide status yellow weather warning for low temperatures and icy conditions came into effect on Sunday evening and remains in place until 11am on Monday. Met Éireann advised that lowest temperatures overnight on Sunday into Monday were between -3 and 1 degrees.
Temperatures are expected to drop further to as low as minus four degrees on Monday and Tuesday night. The forecast for Monday is for a very cold day with widespread ice and frost, Met Éireann said.
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There will be rain on Tuesday that turns to sleet and snow in parts, with the south of the country expected to see slightly drier weather. Highest temperatures during the day will be between three and seven degrees.
Met Éireann said the “bitterly cold” weather was due to continue into Wednesday, with showers of sleet and snow in the north and west of the country.
In Northern Ireland, the PSNI told motorists on Sunday to exercise caution on the roads due to freezing temperatures the night before, particularly in rural areas.
The UK Met Office has issued a snow and ice warning for Northern Ireland, which will be in place from 3am on Monday until 9am on Tuesday. It said snow showers would bring some disruption, warning the public to expect that some roads and railways are likely to be affected with longer journey times on services.
A separate yellow-level snow warning will come into effect for the north-most parts of the region for all of Wednesday and Thursday. – Additional reporting PA