Autumn leaves coated with frost

Frost on autumn leaves

You can almost hear the sound of autumn leaves coated in frost as they crunch under your shoes on a walk through the woods. Though the calendar says it's still autumn, scenes like this highlight the colder temperatures as winter arrives in the Northern Hemisphere.

Radiation frost—the type seen in this lovely photo—is a quick transformation of water vapour to ice. When water vapour in the air comes into contact with surfaces that are at or below the freezing point, the vapour quickly crystalizes into frost. It can make for charming scenery, or a reminder that you should have worn a heavier jacket.