Motorists are being asked to look out for patchy accumulations of snow later today.
Met Éireann has issued a Yellow Alert with up to 3cm of snow expected to fall between 7am today and 6am tomorrow, especially on high ground.
Forecasters have predicted widespread frost and icy conditions this morning with patches of freezing fog and isolated snow showers also.
They say that patchy rain, sleet and snow will slowly extend from the south-west today.
This morning will see sub-zero temperatures that will rise only to between 1C and 5C this afternoon.
The AA's Barry Aldworth says road users should check local weather reports and be aware of conditions before setting out on a trip.
He said: "So what it means for motorists is really the importance of adapting your driving to the weather conditions, that is the first thing that people will have to take into account.
"You'll want to slow down your driving on roads affected by snow and ice and allow yourself extra journey time so that you're not panicking behind the wheel, you're not rushing and racing."