An even colder night is in store tonight as Donegal and 14 other counties are issued with an orange alert.
Temperatures are expected to plummet as low as -7C in northern counties.
As the extremely cold weather continues, widespread severe frost, ice and lying snow will again cause dangerous travelling conditions, travel disruption, and potential animal welfare issues.
The latest low temperature/ice warning is in place from 7pm this Thursday evening until 8am Friday morning for Carlow, Kildare, Kilkenny, Laois, Longford, Meath, Offaly, Westmeath, Cavan, Monaghan, Galway, Roscommon, Tipperary, Leitrim and Donegal.
Road users are asked to assume no road is ice-free, make only essential journeys, take it slowly and allow extra time for travel to reduce risks for all and to relieve the pressure on the emergency services.
A large number of schools and pre-schools in Donegal stayed closed today due to icy conditions. More closures may be expected tomorrow.
