It was really cold this morning, but the hoarfrost on the trees was so strong and looking beautiful, that we lured on a small walk, for sure well dressed.

Hoarfrost is a solid precipitate formed from submerged water droplets of a light mist or directly from the water vapor contained in the air by resublimation.

This requires a very high relative humidity of over 90% and an air temperature of below -8 ° C.

The phenomenon of the formation of hoarfrost occurs comparatively rarely and is often confused with hoarfrost or rime, for which it is a kind of intermediate stage.

The resulting heat is thereby released by convection to the surrounding air, so wind increases the formation of hoarfrost.

The wind must not be too strong, as it otherwise would destroy the sensitive structures.

Above all, contrary to the direction of the wind, needle-shaped ice crystals occur in the form of six-beamed dendrites, which can reach a considerable size and bizarre shapes and usually grow only slowly.

Hoarfrost grows against the wind, as the air coming in on the lungs side carries a higher degree of moisture than in the lee.


A special form of hoarfrost are ice flowers. Tree damage caused by hoarfrost is referred to as a fragrance break in forestry.

Please read as well:

To the Christmas Market in Würzburg

Meteora - Hikes between the towering rocks