There was severe flooding on a number of roads in the south-east, with Kilkenny city badly affected.
At the Met Éireann weather station in the Nore Valley, the highest rainfall since November 1997 was recorded, with close to an inch of rain falling between 9 p.m. on Tuesday and 9 a.m. yesterday.
In Kilkenny city, John's Quay was again flooded. The area was the scene of intense pile-driving by the Office of Public Works in the early summer as part of a €31 million scheme which is still in progress.
Much of the remedial work has been completed and it had been expected that a weir upstream would save the city from flooding.
Just before lunch yesterday, the City Borough Council told residents on the quay that there was nothing to worry about.
By 2 p.m., however, the entire area was flooded. Cars were stranded in the car-park of the city library and the road was impassible.
Kilkenny has seen 130.6 mm of rain so far this month, taking the year's total so far to 112 per cent of the annual average.
A number of roads around the county were impassable or barely passable for much of yesterday.
The road from Kilkenny to Waterford was badly affected, especially at Ballyhale and Stoneyford, where a resident described water "flowing like a river" down the village's main street.
A number of businesses and householders were on high alert amid fears of further flooding, and the national school in Stoneyford remained closed yesterday.
Other areas in Kilkenny hit by the worst of the floods were Kells, Graiguenamanagh, Castlecomer, Ballyraggett, Goresbridge and the section of the main Waterford-Dublin route near Jerpoint Abbey.
Director of services with Kilkenny County Council, Mr Tom Gunning, warned motorists to be wary of possible potholes underneath the flowing water.
In Wexford, there were also reports of localised flooding, with the roads from Larkin's Cross to Taghmon and Kiltealy to Ballymurphy badly affected, along with the N11.
In Waterford, the road from the city to Tramore was closed due to flooding, with local diversions in operation.