A degree of frost is a non-standard unit of measure for air temperature meaning degrees below melting point (also known as "freezing point") of water (32 degrees Fahrenheit or 0 degrees Celsius). "Degree" in this case can refer to degree Celsius or Fahrenheit.
网络释义
1、[气象]霜度
... deflecting vane anemometer 转叶风速仪 deformation field 变形场 degree of frost 霜度 ...
2、冻结度
...day with frost 霜日degree of frost 冻结度; 霜度degrees of frost 冰点以下的度数; 霜度 ...