ST Patrick's Day will be "extremely mild for the time of year", Met Eireann has promised, and the traditional rain should not reach most places until the parades are over.
The State's largest parade in Dublin should even see glimpses of sunshine as it moves off from Christchurch Place at 12 noon on its way down Dame Street, College Green, Westmoreland Street, and O'Connell Street to its finishing point in Parnell Square.
The Dublin parade will feature nearly 20 specially commissioned theatrical pageants on the theme of Irish myths and legends.
Before the parade there will be an international band competition in Westmoreland Street at 9 a.m. and a five km road race starting at Parnell Square at 10 a.m. Along the route from 10.30 onwards there will be a wide range of theatre, music, dance and puppet performers, and at 11.45 a rally of 50 vintage cars. Onlookers are being urged to wear their greenest and maddest clothes to win spot prizes throughout the morning.
The parade route will be closed to traffic from 9 a.m. until sometime after 2 p.m. Burgh Quay and George's Quay will be closed all day for the festival funfair, and the St Stephen's Green area between Dawson Street and Kildare Street will be closed from 1.30 to 7.30 for the Telecom Eireann Monster Ceili, featuring the Kilfenora Ceili Band.
The day's sporting highlights will be the all Ireland club football and hurling finals at Croke Park and the Leinster, Munster and Ulster Schools rugby finals.
Temperatures will be between land 15 degrees C. In the eastern half of the country it will be largely dull and dry. The west will see light drizzle in the morning, which will spread slowly across the country.
Met Eireann's advice is to enjoy the unseasonal weather while it lasts. By the middle of the week the barometer will plunge, with frosty nights and even some snow showers in the north.
In his St Patrick's Eve message, the Taoiseach, Mr Bruton, stressed the festival's religious nature. "We should not forget that we are celebrating a former slave who brought Christianity to Ireland.
"That religious tradition is common to almost all who live in Ireland, and who live in Britain as well. Its central message is one of reconciliation. The violence in Northern Ireland today, the drive to dominate, the continued urge to exploit the `right to march' for the purposes of control over others, are each of them an insult to the Christian message brought to this country by St Patrick 1,500 years ago.
Mr Bruton said this time the Irish people wanted a real IRA ceasefire - "one that will last because it springs from the full acceptance of the logic of peace".
"The logic of peace requires a change of heart for many. The logic of peace means the giving up of traditional rites of domination.
"The logic of peace means apologising for Bloody Sunday, also for Enniskillen and for every shooting, every maiming and every bombing that was done in the past 27 years."