Thousands of people are on the move today and tomorrow as they make their way home and abroad for Christmas.
Dublin airport expects close to a million people to pass through its doors over the holiday season.
A spokeswoman for the Dublin Airport Authority said some 830,000 passengers would arrive and depart this week. Saturday was the busiest day of this week, she said, with next Saturday the second busiest due to people leaving on winter holidays.
Cork and Shannon airports will also be busy, and passengers are advised to allow extra time to get to the airport in the event of road congestion to ensure they comply with check-in and airport security regulations.
Passengers travelling before Christmas are asked not to gift wrap presents as they may be asked to open packages for security reasons.
People will also be on the move around Ireland with Conor Faughnan of AA Roadwatch predicting "a mass exodus out of Dublin" in particular.
Motorists are advised to keep speed down, ensure all passengers wear their seat belts and never drink and drive.
Gardaí have specifically appealed to young people to drive carefully over Christmas, saying those in their late teens and early 20s have been over-represented in road traffic fatalities during the past year.
Iarnród Éireann and Bus Éireann expect to carry over half a million people between them over Christmas and New Year. Passengers are asked to book their seats in advance and to arrive early as services are expected to be very busy.
Dart and Iarnród Éireann commuter services will operate as normal tomorrow, but there will be no services on Christmas Day or St Stephen's Day.
Bus Éireann will operate a normal timetable tomorrow, but services will finish at 9pm and there will be no service on Christmas Day and just a limited Expressway Service on St Stephen's Day.
Dublin Bus nitelink service will operate as normal tonight until 4:30am, but there will be no service on Christmas Eve, Christmas Day or St Stephen's Day. All other Dublin bus services will finish at 9pm on Christmas Eve. There will be no service on Christmas Day, and a Sunday service will operate on St Stephen's Day.
A late Luas service will operate tonight until 3am on the Red line and 3:30am on the Green Line. Christmas Eve services finish at 8pm and there will be no service on Christmas Day. On St Stephens Day, services will start late and operate to Sunday frequency.
Those hoping for a White Christmas will be disappointed, however, Met Éireann is predicting dry, settled weather over the holiday period. However, it will turn significantly colder from St Stephen’s Day onwards.
The Dublin Wicklow Mountain Rescue Team is advising those hitting the hills to walk off the turkey to plan their trip and pack essentials such as a torch and spare batteries, rain gear and a hot flask.
Minister of State at the Department of Transport Noel Ahern and the coast guard also issued a warning about the danger of being swept off cliffs, rocks, piers, harbour walls and beaches around the coast of Ireland.
People are urged to take particular care with Christmas lights and candles over the holidays. Lights should be plugged out and candles extinguished before leaving the house or going to bed.