Some 35,000 people are taking part in the VHI Women's Mini Marathon in Dublin on bank holiday Monday.
The event is now in its fourth decade, and provides valuable fundraising opportunities for charities around Ireland which support people living with illness.
The route goes from Baggot Street, through Ballsbridge before looping around UCD and coming back through Donnybrook to the city centre.
It was set to begin at 2pm and will run until the late afternoon. As always, this will lead to some road closures and travel disruption along the route over the course of the day.
Roads around Baggot Street, Merrion Square and Fiztwilliam Street will be closed from early morning, with Adelaide Road, Pembroke Road, Ballsbridge and Merrion Road all closed at certain points later in the day up until 7.30pm.
This will cause diversions to northbound and southbound Dublin Bus routes serving the south side of the city.
In particular, passengers on the 25, 26, 37-39, 66, 67 and 145 buses can expect delays and route alterations between 6am and 6pm.
Those taking part are reminded that the Luas Red line will terminate at Jervis Street due to works on O’Connell Street, and there will be no train service between Connolly and Dún Loaghaire on Monday because of line improvement works.
After losing the ability to walk due to a brain injury she sustained when she fell off a horse, 45 year-old Wendy Flynn from Meath intends to run the 10km course following months of intensive rehabilitation.
The mother of two is also a cancer survivor, and she has been busy collecting donations for the National Rehabilitation Centre in Dún Laoghaire where she received treatment following the incident.
"The hospital really needs more funding to keep up the valuable services they give to so many like me," she said. "It's such a pity more government resources aren't placed their way," she told The Irish Times.
Nicole Redmond was gearing up to take part in her 22nd consecutive Women's Mini Marathon, and she will be raising funds for St Michael's House where she is a service user.
"This year is very special for me, I am turning 40 in June. I have already achieved 21 mini-marathon medals in total, and I will soon celebrate 20 years working for [CABINTEELY]Bank of Ireland.
“Every year I participate in the marathon, the sense of achievement in crossing the finish line is priceless... I always start my training six weeks before the marathon, training every second day and building up my speed and distance bit by bit,” she added.
Following last year’s washout, the forecast was mixed with sunny spells across the morning in particular but there is a threat of some light rain as the day progresses. Temperatures are expected to peak at 22 degrees, so participants are advised to prepare for every eventuality come start time.
Dublin is not the only place hosting a marathon. Some 10,000 people took to the streets for the Cork City marathon, which started at 9am on St Patrick’s Street. The half marathon starts at 10.45am on Victoria Road.
The curtain comes down on Bloom - Ireland’s largest gardening and food festival- after five day run in Phoenix Park.
Monday marks the last chance for the green fingered to see the festival that showcases gardens featuring work by leading landscapers and designers.
Children are free while adult tickets cost €14.
The Dublin Port River Festival is also likely to draw big crowds to a wide range of family activities including the Festival of Sail displaying large old sailing ships, a river race, Pirate Village with arts and crafts for children, food and entertainment.
Sea-faring types are equally well catered for in Cork where the second Cork Harbour Festival is continuing for the rest of the week.
The festival aims to highlight the importance of the River Lee and Cork Harbour as a natural and cultural resource, and celebrates the communities at the heart of it.
