In Ovid's Metamorphosis, Zeus, thoroughly freaked out* by his encounter with Lycaon, returns to Olympus, determined to rid the world of the evil race of men.
A few lines later, Ovid relates that:
"And now his thunder bolts would Jove wide scatter, but he feared the flames, unnumbered, (the) sacred ether might ignite and burn the axle of the universe: and he remembered in the scroll of fate, there is a time appointed when the sea and earth and Heavens shall melt, and fire destroy the universe..."
Source: Perseus
I can't recall a Greek source for this, aside from Plato:
"...a destruction of the things on the earth by fierce fire, which recurs at long intervals."
Source: Timeaus, 22d
But this very specifically references the destruction of earth (γῆς), and does not include heaven, per the oracle Zeus refers to in Ovid ("ignibus aether" and so forth).
I find it interesting that such a prophecy appears only in the Latin canon, in Ovid, who was born a year after Julius Caesar was assassinated, by which I mean to say, during a period when there had been documented contact with the Germanic tribes for well over a century.
Q: Are there any Greek sources for the destruction of the Universe by fire? Is it possible this prophecy derives from Germanic sources?
I say freaked out because Zeus is "anxious" about his future sovereignty over the world, and goes on to suggest that nothing is safe if he himself can be "ensnared" by a psychopath such as Lycaon.