One of Northern Ireland's busiest roads has been closed because of collapsed overhead power lines.
Police shut a stretch of the M2 motorway between Antrim and Templepatrick on the northern outskirts of Belfast as electrical engineers repaired the damage, which they believe was linked to the extreme weather conditions.
With no immediate sign of a thaw and overnight temperatures as low as minus 15C in some parts, gritters were out on most of the main roads.
Police warned Christmas Day drivers of icy and treacherous conditions. Fermanagh, Tyrone and Londonderry remained some of the areas hardest hit by freezing fog and snow.
Virtually all outdoor sporting events on Boxing Day have been called off, but officials of the Ulster branch of the Irish Rugby Football Union appealed for fans to help clear snow off the pitch at Ravenhill, Belfast, on Sunday in advance of Ulster's Magners League match against Leinster on Monday afternoon.