Thursday's meeting at Clonmel, featuring the Grade Three Surehaul Mercedes-Benz Novice Hurdle, is off due to waterlogging at the course.
An inspection took place at noon today as the course was found to be unfit for racing on Tuesday.
Following a further 3.5m of rain overnight, the inspection found little improvement.
Paul Moloney, IHRB clerk of the course at Clonmel said: "Following 3.5mm of rain overnight, the track here at Clonmel remains unfit for racing and the fixture scheduled for tomorrow has been cancelled.
"Unfortunately we have had 52.5mm of rain since entries and Met Éireann have forecast a further 4-5mm of rain between now and racing.
"The team in Clonmel will liaise with Horse Racing Ireland and other stakeholders to reschedule the meeting in due course."
British racing has also been hampered by bad weather.
Wetherby's jumps card on Wednesday was abandoned due to a waterlogged track.
There will only be one jumps fixture held on Wednesday in the UK, taking place at Hereford.
