Sunday was due to be the final day of the four-day festival, which began on Thursday.
The Camp Bestival event is aimed at families and is linked to Bestival, which is due to begin this coming Thursday at the same site.
Organisers said in a statement on Twitter: “We are utterly devastated and heartbroken to say that we have been advised by our safety teams that we cannot re-open arenas again today due to the severe weather and the forecasting of continual high winds and rain today.”
They added: “This has been such a tough decision but the safety of all you guys, the families, kids, and our working staff has to be of paramount importance.”
The statement said that a refund policy will be issued as quickly as possible. Revellers are welcome to continue to camp overnight at the site, though many have already chosen to pack up and leave.
The Met Office had issued a yellow weather warning for severe gales and heavy rain as last week’s heatwave was punctured by blustery conditions.
On Saturday, the Camp Bestival audience was stunned when TV baking supremo Mary Berry joined legend Rick Astley on stage - to perform as his drummer.