Motorists were urged to drive with care today as patches of ice developed on roads overnight.
Met Éireann expected temperatures to fall to minus two degrees Celsius in places while fog will also affect some areas of the country.
AA Ireland said drivers should take particular care in counties Monaghan, Leitrim, Meath, Offaly and Wicklow, especially on back roads and in sheltered areas.
“Reduce your speed, keep a safe distance from the vehicle in front, use your fog lights in poor visibility but don’t forget to turn them off afterwards,” said a spokeswoman.