Katesbridge in County Down recorded a temperature of -7°C, the lowest overnight reading of the winter in Northern Ireland. The cold snap followed a dry, chilly spell across the region.
A yellow warning for snow and ice was issued by the Met Office, valid from midnight on Thursday until 10:00 GMT on Friday. Icy stretches were expected on untreated surfaces during the warning period.
Snow showers were forecast for early Friday, with patchy accumulations of 1-2 cm, especially on higher ground. A strong northerly wind was expected to increase wind chill and lower daytime temperatures.