What are the climatic characteristics of Jiashan in autumn and winter?

Jiashan is located in the East Asian monsoon region on the southern edge of the northern subtropical zone, with four distinct seasons, mild and humid, abundant sunshine, abundant rainfall and long frost-free period, which is suitable for crop growth. However, located in the mid-latitude coastal zone, the climate changes obviously, with the characteristics of wet in spring, hot in summer, dry in autumn and cold in winter. The main disastrous weather includes rainstorm, continuous rain, drought, cold wave, heavy snow, fog, high temperature and typhoon. ?

The average temperature over the years 15.9℃, 65438+ 10 is the coldest, the monthly average temperature is 3.8℃, and the extreme minimum temperature-10.8℃ appears in 1977+3 1. It is the hottest in July, with an average monthly temperature of 27.9℃ and an extreme maximum temperature of 38.7℃, which appeared on July 25th, 2003. In spring, the average daily temperature stably passed the average initial day of April 210℃; The average daily temperature in summer is stable through the average first day of June 13, 22℃; When the average daily temperature in autumn is lower than 22℃, the average first day in September is18; The average daily temperature in winter is lower than165438+1the average in early October 19℃. The average number of days when the daily maximum temperature is ≥35℃ is 7.7 days, and the highest number is 28 days in 2003. ?

Over the years, the average first frost day was1October 1 14, the last frost day was March 25th, and the average frost-free period was 233.6 days. The average first freezing day is165438+1October 29th, and the average annual freezing day is 39 days. ?

The average rainfall over the years 1 153.8 mm, and the rainfall in the most years 1683.4 mm appears in 1999. The minimum rainfall is 695. 1mm, which occurs at 1978. The annual average rainy day is 138.5 days, and the maximum daily precipitation is 167.6 mm, which occurred on1August 22, 977. There are two relative rainy and dry seasons throughout the year. April-July is the first rainy season, in which April-May is spring rain, June-July is plum rain, and July-August is controlled by subtropical high, with high temperature and little rain. The second rainy season is from late August to September. Affected by typhoons and cold air, rainfall increased significantly. The precipitation began to decrease from 10, which became the second rainy period. The average number of days of snowfall over the years is 7.6 days, with the maximum of 3.4 days in 65438+ 10. The maximum snow depth is 17cm, which occurred in 1984+1October19. ?

The average sunshine hours over the years are 1, 947.2 hours, of which1~ February is the least, and the average is below 1.25 hours. July and August are the most, with an average of more than 220 hours. ?

The average annual wind speed is 3. 1 m/s, and the average number of windy days with instantaneous wind speed ≥ 17 m/s is 5.4 days. The maximum wind speed over the years was 35.5m/s (12), which occurred on March 6, 1987.