The Forever Young music festival has announced that day visitors "can not be admitted to site" today due to weather conditions.
Organisers of the Co Kildare festival said anyone present on the site will be unaffected and they "intend to run the show to a reduced audience".
In a statement posted online, the festival said: "We are heartbroken to bring you this news, but everyone's safety has to be our priority. Saturday ticket holders and weekend no camping ticket holder sadly can not be admitted to site."
In a Facebook video, the festival's founder Sharon Alston apologised to those day ticket holders.
She said that the reason for the postponement was due to safety concerns.
Ms Alston said there are "limited capacities on safe evacuations of the site" in certain conditions.
She said it would not have been safe to allow extra people on the site.
Ms Alston said that the organisers worked through the night to try resolve the issue but added that they "cannot jeopardise anyone’s safety".
She said the organisers will provide further updates on social media.
Acts performing at the festival today include Erasure's Andy Bell, Billy Ocean, Tony Hadley and Go West.
Met Éireann warned of unseasonably strong winds for coastal areas of Galway, Mayo and the off-shore islands.
