A status yellow low temperature/ice warning is in place for 17 counties this morning (Monday).
A similar advisory has been issued by Met Éireann for Snow and Ice for Cavan, Donegal, Monaghan, Connacht and Louth.
It means the whole country is under a status yellow weather warning until 11am.
Met Éireann is warning that many counties will be affected by frost, ice and freezing fog patches this morning.
Parts of the north and west were hit with snow showers in some areas.
Forecasters are appealing for road users to be cautious.
Temperatures were below freezing in many areas overnight, with Met Éireann warning of 'treacherous' travelling conditions throughout the day.
A number of schools in Donegal will be closed today and in the North a significant number will remain closed due to the weather conditions.
The UK Met Office has issued a yellow warning for snow and ice for Antrim, Armagh, Down, Fermanagh, Tyrone, Derry with the potential to cause disruption to travel today.
