There are patches of extremely dense fog this morning.
A nationwide status yellow fog warning is in place until eleven o'clock this morning.
Motorists are being advised to drive with extra care and use fog lights when necessary.
Offaly's Cathal Nolan from Ireland's Weather Channel is warning of patches of extremely dense fog in some parts of midlands, with visibility reduced to 100 metres or less in places.
He says the conditions are likely to continue into the afternoon: