A status yellow fog warning will remain in place for 14 counties until eleven o'clock this morning.
The counties under the alert are Carlow, Dublin, Kildare, Laois, Longford, Louth, Meath, Offaly, Westmeath, Wicklow, Cavan, Monaghan, Leitrim, Roscommon.
Met Eireann says dense fog is making for difficult or dangerous driving conditions.
