Met Eireann has issued a Status Orange snow-ice warning for Dublin, Kildare, Louth, Wexford, Wicklow, Meath and Waterford
The forecaster is expecting scattered heavy snow showers which will lead to accumulations in places and some drifting.
The warning is valid from 3am on Sunday morning until 12pm on Sunday afternoon.
There is also a Status Yellow snow-ice warning in place for the rest of the country
The forecaster states it will be very cold this weekend with wind chill and icy patches. Snow showers also but some areas staying dry, especially the northwest. That warning is in place from 12pm on Saturday until 9am on Monday
The forecast for St. Patrick's Day is for a cold and windy day with showers progressively turning more wintry. Most of the showers will be in the east, but a few will reach the midlands and south as well. Some accumulations of snow on high ground at first, but on lower levels later as well. Highs of only 1 to 3 degrees in the eastern half of the country, 4 to 6 degrees in the west. Blustery easterly winds will add a significant wind chill.