What are the signs of thunder in winter?

Thunder in winter means cold and snowy weather.

Through the long-term careful observation of the phenomenon of "thunder in winter", the public summed up the law of "thunder and snow in winter", that is, thunder in winter means that the air humidity is high and it is easy to form rain and snow; There is also a folk saying that "when it thunders in winter, ten cowsheds are empty", which means that when it thunders in winter, the warm and humid airflow is very active and the cold air is also very strong. It's so cold and snowy that even cows may freeze to death.