Police have advised motorists to take extra care, as a Met Office snow warning for Northern Ireland remains in place.
Bitterly cold conditions along with showers during Sunday and into Monday morning bring the increased risk of snow, especially on higher ground.
Icy stretches are also likely to form on untreated surfaces, the Met Office said.
Its warning to be aware of snow and ice is in place until 12:00 GMT on Monday.
Amid the risk of icy conditions on the roads, police said motorists should slow down and keep a safe distance from cars driving in front.