If you are heading out on the roads in the next 24 hours, watch out for snow and ice.
A snow-ice warning for much of the nothern half of the country has just been upgraded by Met Eireann to Status Orange.
It applies to Cavan, Monaghan, Donegal, Longford, Leitrim, Mayo and Sligo.
Between four and eight centimetres of snow are expected this evening, tonight and tomorrow.
Snow at my house, Co Antrim, N Ireland. 😀 pic.twitter.com/B3VcSV7e3r— Lorraine Mulholland (@lorraineelizab6) December 7, 2017
The RSA is reminding people to clear windows and mirrors before setting off and to carry a scraper and de-icer.
Drivers should brake gently and leave plenty of distance from the vehicle in front, as stopping distances are 10 times longer in ice and snow.
Temperatures are already dropping and wintry showers are expected in places after dark.
Met Eireann Meteorologist Pat Clark says the early hours of this evening will probably be okay for commuters.
He said: "The further into the nights hours you go, the more tricky it is going to become, but in Ulster the showers could turn into sleet and snow quite readily once it gets dark.
"After tea and before midnight there could be wintry showers of sleet and snow turning up almost anywhere.
"In Ulster from the word go after dark, Connacht, the Midlands and Leinster in the mid to late evening and then from midnight on in parts of Munster and south Leinster."