WISCONSIN (WLUK) -- It was a magical scene on Christmas morning for Northeast Wisconsin.

Trees were surrounded by fog which froze on the branches-- giving us what's called a "hoar frost."

The National Weather Service defines hoar frost as "a deposit of interlocking crystals formed by direct sublimation on objects, usually those of small diameter freely exposed to the air, such as tree branches, plants, wires, poles, etc."

It is also described as being similar to dew but the object that's frosted must be below freezing.