We’ve had several days of fog, either just in the early morning or most of the day. On Monday the day started bright but slowly got darker and darker as the fog rolled in from the north. The trees formed hoar frost before the sun set and by Tuesday morning all was completely draped in lacy white. I love this type of frost because it so changes a mundane scene into something special. Today the sun broke through in the afternoon gracing us with a coral and pink sunset. My camera isn’t the best – maybe Santa will bring me a new one!
Activity: There are different types of frost, depending upon the atmospheric conditions when it’s forming. Hoar frost forms when the temperature of any vegetation is lower than the surrounding highly moisturized air. Water droplets from the fog condense on leaves, branches and stems. Since the tree or grass is colder than the air, the droplets freeze forming icy crystals that build layer upon layer.
You can make your own fog with some dry ice. Most grocery stores carry dry ice – ask for some for your ice cream! Always wear gloves when handling dry ice and never let children play with it by themselves. We always just put it in the sink with a little water and let the fog form! Experiment with different containers and some tubing (like that for dryer vents) so you can have more control over your fog.
The word “hoar” originates from Old English and Norse and is used to describe something that is gray with age, as in a white-haired elder. Hoar frost often forms at night – turning young vegetation old and “white-haired” as you sleep!