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Soft rime occurs in misty and windy weather when the air temperature is - 2 to  -7° degrees; such rime has no crystalline structure, and its surface is bumpy, created by sub-cooled mist drops on fast freezing. 

When the weather turns to thaw, such rime changes into glaze frost because the amount of moisture increases. This may become very dense and heavy – dangerous for trees as well as power lines.

 

When air temperature falls and the wind decreases the density of the rime decreases, and it changes into interesting crystalline rime. As  light conditions improve interesting photos can be made.

 

 

White frost has a delicate structure, being composed of dense ice crystals. So a crystalline lace is created that spills down already at slight shaking. Such frost forms as a rule with a clear sky or in cold and windless weather, with the aid of mist or a mist haze, but sometimes simply by cold – there must be at least  -11 ... -25°C degrees of cold.

 

 

Frost on parsnip