Hoar frost blankets trees in the Secret Garden in Inje, 118 kilometers northeast of Seoul, for the first time this year on Nov. 6, 2024, heralding the arrival of winter. (Yonhap) (END ...

The interaction between the warmer wet air and the cold dry air just above it, can condense as hoar frost-like crystals on the ice surface. This process requires very little to no wind.