202 1 the first frost is the weather change of the first frost.

1, 202 1 The first frost was1202 10/2: 36 on October 23rd.

2. The "first frost" solar term 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. On the national average, the first frost is the season with the largest temperature difference between day and night in a year. After entering the first first frost solar term, the cold air activities affecting our country became more and more frequent, and the temperature difference between day and night increased rapidly. Especially in Jiangnan and South China, the temperature fluctuation is becoming more and more obvious, while some areas in the northwest and northeast have shown the scene of "cold wind falling leaves" in early winter. During the first frost, generally from late June 10 to1early October110, warm and humid air is marginalized because of the gradual unification of dry and cold air, and many weather with the characteristics of summer and early autumn exits, making the weather relatively more severe.