out to the watch a parade and enjoy the "ceol agus craic" (music and fun) of Ireland's national day.
Revellers attend St Patrick's Day festivities in Dublin. More than 100 parades are being held across Ireland to mark St Patrick's Day, the feast day of the patron saint of Ireland, with up to 650,000 spectators expected to attend the parade in Dublin. Photo: AFP/ Peter Muhly
"There's been lots of colour and loads of performers and marching bands this year," said Edelle Moss, chief executive of Ireland's St Patrick's Day Festival.
"We have our largest ever number of international participants in the Saint Patrick's Day parade with a very strong procession of over 46 different countries," she added.
As part of an initiative called "The Gathering", the government is encouraging people with Irish ancestry -- which by some estimates includes up to 60 million people worldwide -- to visit the motherland in 2013 in a bid to boost tourism.
A total of 225,000 passengers are expected to pass through Dublin airport over the weekend, while the Dublin Chamber of Commerce expects city companies to bring in 50 million euros ($65 million) from the festivities, in a welcome boost to the struggling eurozone economy.
Across the world, some 70 landmarks from Egypt's pyramids to the Sydney Opera House have been lit up green in honour of St Patrick's Day.
In Dublin, the Guinness brewer rolled out the "green carpet" to everyone with the name Patrick, welcoming them for free into their factory tour on the banks of the River Liffey.
People called Patricia, Paddy, Padraig, Trish, Tricia or Patsy were also given the VIP treatment.
The annual All-Ireland club finals of the Celtic nation's national sports, hurling and gaelic football, attracted thousands of supporters to the city's Croke Park stadium.
While many took refuge from the weather in Dublins pubs to have a few glasses of the "black stuff", organisers worked hard to take the focus away from alcohol.
The festivities have become associated with scenes of drunken disorder and underage drinking, leading to changes in the law to restrict pub and liquor store opening hours.
"There were quite big problems a couple of years ago but in recent years it has improved," Fionnuala Sheehan of Drink Aware told AFP.
"A lot of that has to do with the fact there's a great deal of effort being made into making lots of events appealing to all age groups."
Even Pope Francis took a moment out of the hectic schedule of his first few days in office to send his wishes to the Catholic nation, in a note to President Michael D. Higgins on Friday.
"It is one of the first messages Pope Francis has sent and he said, 'I am pleased to send greetings to you and your fellow citizens on the happy occasion of Irelands national day'," Higgins told national television.
"At the beginning of my pontificate I commend the nation to the powerful intercession of Saint Patrick and assure you of my prayers for the beloved people of Ireland, that they may enjoy peace and prosperity," the pope said.