Further snow and icy conditions are expected to cause disruption in parts of Northern Ireland and the Republic over the coming days.
A yellow weather warning is in place for Northern Ireland until noon on Wednesday with further wintry showers forecast.
The north west area has been worst affected so far with some schools closed in Londonderry, disruption to public transport and a number of road accidents occurring in treacherous conditions.
The Met Office expects snow showers to continue into Wednesday, with up to 10cm in some higher areas.
The coldest temperature recorded overnight in Northern Ireland was in Katesbridge, County Down, where it reached minus 8.4C.
In the Republic, temperatures dropped as low as minus 7C and some schools in Donegal and Cork were shut.
A status yellow snow and ice warning is in effect for counties Donegal, Leitrim, Sligo until 9am on Wednesday.
A separate snow and ice warning for counties Cavan, Monaghan, Cork, Kerry, Longford, Louth, Meath, Offaly, Westmeath, Mayo, Roscommon came into effect on Tuesday evening and will remain in place until Wednesday morning.
Met Eireann said there will be scattered snow showers and icy conditions in some areas.
