black frost
From Glossary of Meteorology
- A dry freeze with respect to its effects upon vegetation, that is, the internal freezing of vegetation unaccompanied by the protective formation of hoarfrost.
A black frost is always a killing frost, and its name derives from the resulting blackened appearance of affected vegetation.
- Among some fishermen, a steam fog that extends above the bridge level of the fishing boats.
If the steam fog does not reach this height, it is a white frost.
