A status orange weather warning has been issued for Donegal this afternoon due to freezing fog.
Donegal is among the counties to experience below-freezing temperatures throughout today.
There is also a risk of snow in the northwest, Met Eireann says.
The severe weather warning is in place until midnight while a status yellow alert takes over until 10am Tuesday.
As the arctic blast continues until Friday, people are being warned to watch out for treacherous conditions on paths and roads, travel disruption, burst water pipes and damage to engines.
Tonight will remain very cold tonight with lowest temperatures generally ranging from -6 to -2 degrees in northern counties.
