Backyard Hoarfrost Crystals

February 18, 2016

Frost art

Photographer: Ralph Winrich
Summary Authors: Ralph Winrich; Jim Foster

The photo above shows delicate ice crystals on the branches of a small plant in my backyard near Stoughton, Wisconsin. The temperature at the time the picture was taken was about 27 degrees F (-3 degrees C) -- the sky was overcast. It seems likely that this is hoarfrost and not rime ice. These crystals grow best when the air is very moist and the temperature is below freezing, sometimes well below freezing. Often the source of the moisture is a nearby stream or lake and, on occasion, a remnant snow pile. These elongated crystals began to sublimate/melt soon after being exposed to the morning Sun. Photo taken on January 22, 2016.
Photo Details: Nikon D 80 camera; 18-135 mm lens (set at 135); ISO 400.