Two Met Office weather alerts remain in place for snow and ice across Northern Ireland.
The warning is in force until noon on Monday.
People have been urged to be careful when out and about, while some sports fixtures have been hit.
Two top flight games are off, with five of the six Championship fixtures also postponed.
The Department for Infrastructure said on Saturday morning: “Temperatures fell below freezing overnight and there is a risk of ice and snow on roads.
“A Met Office yellow warning of snow and ice for Northern Ireland is in place valid until 12 on Monday.
“Salting of roads on the scheduled network (including the deployment of snow ploughs on higher ground routes) took place overnight and this morning. Road users are advised to exercise caution when travelling, particularly when driving on untreated roads.”
The Saturday afternoon sporting programme has also been affected.
Winter weather in Co Armagh on January 2. Luke Jervis/Belfast Telegraph
This afternoon’s Premiership clashes between Ballymena and Glenavon, and Portadown v Cliftonville are off after pitch inspections.
Championship games between Ards and Limavady and Newington v Dundela have also been called off after failing pitch inspections. Also off are Loughgall v Ballinamallard, Queen’s University v Warrenpoint and Annagh United v Institute.
Dergview v Knockbreda and Ballyclare Comrades v Newry City in the third tier are off.
Further pitch inspections will take place ahead of several other games.
These include the Coagh v Dollingstown and the Strabane Athletic v Lisburn Distillery fixtures in the Premier Intermediate League.
People have been warned that the cold weather will last through the weekend.
One weather warning came into place from 3pm on Friday and will last until noon today.
The Met Office said wintry showers will become more widespread, and will likely bring some disruption to travel.
A second alert will then come into force from 3pm today until noon on Monday, although it does not include Co Fermanagh.
Winter weather in Co Armagh on January 2. Luke Jervis/Belfast Telegraph
A spokesperson said: “Snow showers will continue to affect many parts of Northern Ireland over the weekend, before gradually easing on Monday.
“The heaviest and most frequent snow showers will be in the north, although along the north coast these may fall as rain or sleet at times.
“Whilst not all locations in the warning areas will see snow, around 1-3 cm is expected to have fallen in many places by Monday morning, with the potential for 5-10 cm to build up in a few locations, especially over higher routes, such as Glenshane Pass. Ice will be an additional hazard for many.”
Snowy scenes on Cavehill Photo: Gareth Hanna for Belfast Telegraph
The spokesperson added: “All of Northern Ireland will remain bitterly cold over the coming days. Overnight lows are expected to dip to at least -2 or -3C, with rural spots potentially seeing even lower values.
“Daytime temperatures will generally reach the low to mid-single figures, but rural areas, especially those with higher ground or lying snow, may struggle to rise above freezing.”
The Met Office said there was potential for up to 10cm of snow in higher areas like the Glenshane Pass.
Police have alerted drivers to take additional care when driving amid “treacherous” conditions on the roads as a result of the snow and ice warning in place.
A Met Office spokeswoman said: “We expect this cold spell to persist into the weekend and on into next week, with further warnings possible as temperatures remain well below average and snow showers continue in places.”
Cold weather is also causing problems in the Irish Republic.
A yellow alert for Co Donegal came into effect at 8pm last night and is valid until 11am, amid warnings of wintry showers “with some snow accumulations”.
A separate Status Yellow low temperature and ice warning has been issued for several counties.
Meanwhile, the UK Health Security Agency (UKHSA) has issued warnings across England for the start of the year, which are in place until 10am on January 6.
The UKHSA said it means the weather is “likely” to cause significant impacts across health and social care services, including a “rise in deaths” among those with health conditions or aged 65 or over.
The PSNI recommended that motorists driving “exercise extreme caution” and leave additional time for travel today
News Catch Up – Thursday 1 January
Dr Paul Coleman, consultant in health protection at the UKHSA, said: “The weather is forecast to be very cold across England over the coming few days.
“Low temperatures like these can have serious impacts on the health of some people, particularly older people and those with serious health conditions.
“Exposure to cold can lead to increased risk of heart attacks, strokes and chest infections.
“It is therefore really important, as the colder weather sets in, to check in on friends, family and neighbours that are most vulnerable.”