The weather could be a dampener this bank holiday weekend, with forecasters saying people should be prepared for heavy showers, as the weather will be "unsettled and changeable".
Mr Pat Clarke, forecaster with Met Eireann, said the weekend will be fresher and cooler than the warm, sunny and humid conditions of the past few days. Temperatures are predicted to be in the high teens, rather than the low-20s.
Tomorrow, rain is predicted in the south and south-west, spreading over the rest of the State as the day progresses. All areas will experience heavy rain on Sunday, but it will pick up in the south in the afternoon, he said. Monday will be cool and fresh.
Iarnrod Eireann is operating 30 special trains, in addition to its regular services, to carry an estimated 200,000 people. A spokesman said demand is to peak from lunchtime today until the same time tomorrow, particularly from Heuston Station, Dublin. People who can travel at other times are advised to do so.
Thousands of GAA fans are expected at the major Gaelic football fixtures - Kerry and Dublin, in Thurles, tomorrow and Meath and Westmeath, in Dublin, on Sunday.
Iarnrod Eireann said advance purchase of tickets was essential for the extra services from Heuston Station and Tralee, for Thurles, and from Mullingar and Enfield, for Dublin.
The Witnness festival at Fairyhouse racecourse tomorrow and Sunday, will feature 80 acts on five stages.
Normal DART services will operate, except on Monday when the timetable will be the same as Sunday, with minor alterations.
A Sunday service will operate on the Dublin-Drogheda route on Monday, while there will be no suburban trains on Monday on the Dublin to Arklow, Kildare and Maynooth routes. An estimated 100,000 people will be transported on Bus Eireann's expressway and provincial services.
The weekday timetable will operate today and tomorrow, with additional buses on major routes. There will be the usual Sunday services, with some alterations and cancellations.
On Monday, services will operate as on Sundays, with a number of alterations. Normal weekday services will operate on the following routes: Dublin-Belfast, Cork-Galway, Tralee-Sneem, Waterville and Ring of Kerry, Killarney-Dingle, Slea Head, Castletownbere.
The Dublin, Cork and Shannon airports will cater for an estimated 363,000 passengers. Dublin Airport expects to handle 276,000 passengers, an increase of 4 per cent on last year. Over 370 holiday charter flights will operate from the airport.
Over 29,000 passengers will travel through Cork Airport, an increase of 5 per cent, while the 58,000 passing through Shannon represents a 5 per cent increase.
The threat of disruption at the airports was averted, following intensive negotiaions, writes Industry and Employment Correspondent Padraig Yeates.
Airport police and fire service personnel have deferred an overtime ban, due to begin at 7 a.m. tomorrow at Dublin, Cork and Shannon airports.
Meanwhile, Stena Line expects to carry 57,000 passengers and 10,000 cars on the Dun Laoghaire-Holyhead, Dublin-Holyhead and Rosslare-Fishguard routes. Irish Ferries will transport about 44,500 passengers and 10,500 vehicles on their Dublin and Rosslare to Britain routes, as well as about 8,000 passengers and 2,350 vehicles on the Rosslare to France route.
For more information on travel and festivals around Ireland, see Explore Ireland at www.ireland.com/explore/