Some 40,000 women are to take part in the Flora Women's Mini-Marathon today in what is expected to be one of the hottest days for the event yet.
Dublin is forecast to reach 24 degrees and participants have been advised to wear plenty of sunscreen and bring a bottle of water.
The 24th annual race, which is the biggest event of its kind in the world, will begin at 3pm at Fitzwilliam Square. Organisers hope to raise up to €10 million for a variety of charities around the country.
The fastest participants are expected to complete the course in about 35 minutes, while average walkers should finish it in two hours. Some 28,000 entrants are from Dublin.
Possible winners include Pauline Curley from Co Offaly, Orla O'Mahony and Niamh Devlin from Dublin, Niamh O'Sullivan from Co Kerry, and Eimear Martin from Co Louth.
The good-humoured event will feature 14 bands who will play at various points along the route and at the finish in St Stephen's Green.
Although the mini-marathon is women only, organisers are expecting a small number of men in disguise to take part. A costume competition, run by sponsors Flora on the theme of heart health, should also add colour. And for the first time the mini-marathon will be televised on Setanta tomorrow evening.
The 10km route on the southside of the city takes in Mount Street and Northumberland Road and reaches as far as St Vincent's Hospital on Merrion Road before turning at Nutley Lane and going back to St Stephen's Green via Stillorgan Road and Leeson Street.
Roads in the vicinity of the route have been closed to traffic from early this morning and are expected to reopen between 4.30pm and 6.30pm. Traffic diversions will be in place all day at Mount Street, Northumberland Road, Lansdowne Road, Pembroke Road, Ballsbridge and Merrion Road. From 2.45-5.30pm there will be diversions at Nutley Lane, Stillorgan Road from Belfield to Donnybrook, Donnybrook village, Morehampton Road and Leeson Street.
Spokeswoman for the marathon Catherine MacNeill said that since the event began in 1983 more than €85 million had been raised for Irish charities and there was a possibility that the figure could reach €100 million this year.
She warned participants to wear sunscreen and bring a bottle of water to cope with the high temperatures expected in the city this afternoon. "Walkers in particular can be waiting around for a long time at the start and if they drink their water they can top it up from drink stations at the starting line, on Stillorgan Road and at the end."
