A status yellow low temperature and ice warning is in place.
The lowest temperatures of the year were recorded last night, dropping to at least minus-seven degrees in places.
A status yellow low temperature and ice warning will remain in place countrywide until 12 o'clock this afternoon.
Met Éireann is warning of treacherous conditions on the roads, with severe frost and freezing fog.
Offaly's Cathal Nolan, from Ireland's Weather Channel, says it was extremely chilly overnight:
Government Considers Compulsory Helmet Use For E-Scooter Riders
Westmeath Family Blogger Backs 'Mental Health' Days
Enterprise Minister Confirms He Was Overpaid
Offaly Driving Instructor Calls Out Lack Of Clear Road Markings
Occupied Territories Bill Needs Enactment - Brian Stanley
Laois Gaelscoil To Reopen In Time For 20th Anniversary
Enoch Burke To Be Re-Arrested For Repeated Trespass
Laois Brothers Sentenced Over Rape And Assault Charges
Laois TD Questions EirGrid On Energy Capacity
Westmeath Library Re-Opening Pushed Back
Government Action Urged On Prison Conditions
Offaly GAA Club Submit New Pitch Plans
Gardaí Attend Scenes Of Midlands Crashes
Midlands Counties See Dramatic Fall In Housing Commencements
Westmeath Councillor Calls For Baby Loss Certificate Scheme
Commemorative Walk For Ashling Murphy To Take Place In New York
Sentencing Adjourned For Offaly Father Whose Son Died In Arson Attack
Gardaí Seize Heroin, Crack Cocaine And Cash In Offaly Town
Opposition TD Calls For Minister Overpayment Ultimatum
Investigation Underway After Suspected Arson At Westmeath Home