What are the weather characteristics of the first frost and the first frost?

1. The first frost is characterized by cold weather in the morning and evening, hot weather at noon, large temperature difference between day and night, and obvious autumn dryness. As far as the national average temperature is concerned, "first frost" is the season with the largest temperature difference between day and night in a year.

2. After entering the first first frost solar term, the cold air activities affecting China have become more and more frequent, and the temperature difference between day and night has increased rapidly, especially in Jiangnan and South China, and the temperature fluctuation has become more and more obvious. Some areas in the northwest and northeast have shown the scene of early winter with cold wind and falling leaves.