Hoar frost is a type of feathery frost that forms as a result of specific climatic conditions. The word ‘hoar’ comes from old English and refers to the old age appearance of the frost: the way the ice crystals form makes it look like white hair or a beard. (Click on the image below to enlarge)
The size of the frost that forms depends on how much water vapor is available to ‘feed’ the ice crystals as they grow. Hoar frost has a distinctive appearance as it forms hair-like or feathery structures as it grows. Hoar frosts don’t damage established trees and shrubs.
Here are some more icy photos I took this month February 11, 2021. (click on images to enlarge)