I have an Earth-like planet that has no frozen poles. It is very similar to a Cretaceous Earth. Is there any sort of odd, yet reoccurring weather event, that could cause freezing air from the upper atmosphere to descend quickly to lower the temperature of several islands in a non-polar latitude down to freezing?
Edit: By freezing an Island, I mean allowing water to get cold enough to form ice on the island, resulting in a colder climate than surrounding areas.
Edit: My world has large oceans uninterrupted by any continents, with the world's only two terrestrial continents being at the poles and dominated by forests. This island is volcanic in nature, so having a higher elevation isn't unreasonable.