It will be very cold this morning across Ulster with widespread sharp or severe frost and icy stretches on roads.
The frost will gradually clear through the morning and today will be dry with plenty of sunshine, says Met Éireann.
Highest temperatures of 7 to 9 degrees with light to moderate southeast breezes.
Tonight will be cold and dry with clear spells in most areas.
It will be a bit cloudier at times in the south with a few spots of coastal drizzle.
Lowest temperatures of -3 to +2 degrees with frost and some icy patches and light southeast breezes.
Tomorrow morning, frost will gradually clear.
There will be good sunny spells. However, cloud will increase from the south through the afternoon and evening.
Light southeast breezes will increase moderate to fresh and it will be quite cold with highest temperatures of 5 to 7 degrees.