Ask God for help about the four seasons in Aershan.

Aershan has a special geographical environment, and its altitude gradually rises from southwest to northeast. It is mainly affected by the warm and humid air flow in the southeast ocean and the dry and cold air flow in the northwest all year round. It belongs to the cold temperate continental monsoon climate and continental alpine climate zone, with obvious local microclimate characteristics. The annual temperature is low, the frost-free period is short, and the annual and daily temperature differences are large. Aershan city has unique characteristics of four seasons, that is, spring and autumn are connected, summer characteristics are not obvious, and winter is long and cold. The seasonal changes of light, heat, water and wind are obvious. From spring to autumn, the average start date of spring in Aershan City is May 6th, the average end date of autumn is September 20th, and the connecting time between spring and autumn is about 138 days. In spring, the temperature rises quickly, the daily temperature difference is large, and the cold and warm air alternate frequently, with occasional snowfall and "late spring cold". Precipitation variability is large, and spring drought is less. The windy days have increased. The highest temperature in the whole year appears at 7 o'clock, while precipitation increases, water vapor is abundant, and strong convective weather such as rainstorm and hail occurs frequently, which is harmful to crops, but the same season of water and heat is the peak season for crop growth. From late August to mid-September, the temperature dropped obviously, the precipitation decreased obviously, the temperature difference between morning and evening was large, and autumn frost appeared. The frost-free period of the year is about 90 days. Winter The winter in Aershan is long and cold, with an average start date of 2 September1and an average end date of 5 May, lasting more than 7 months (227 days). Due to the influence of northwest cold air and the control of Mongolian high pressure, the cold air mass stays for a long time and there are many cold waves and snowfalls. The severe cold period lasts for more than 3 months, and the snow-covered period 152.2 days. The average snowfall in winter is 30mm, accounting for 6.5% of the annual precipitation. The extreme minimum temperature is -45.7℃, appearing in 19665438+1October19. Occasionally there will be strong winds. The total solar radiation in Aershan City of Rizhao is 5275 MJ/m2, and the total radiation in the crop growing season accounts for 66-69% of the annual value. The annual sunshine duration is 2468 hours, and the average annual sunshine percentage is 56%. The monthly sunshine distribution is the largest in May, with an average of 255.3 hours. The minimum is 65438+February, with an average of 140. 1 hour. The temperature, humidity, air temperature and temperature difference between north and south in Aershan are very different from those in winter in Xia Han. The annual average temperature is -3. 1℃, in which the temperature in Wuchagou, Xikou and Mingshui areas in the south of Bailang area is getting higher, and the temperature in the north of Bailang area is lower. The average temperature in Leng Yue of Aershan is -25.6℃, and the average maximum temperature is 16.6℃. The accumulated temperature above 0℃ is 1898.5℃, above 5℃ is 1738.3℃, above 1345.9℃ and above 15℃ is 520℃. Humidity The water pressure in Aershan decreases with the elevation. It is the largest in summer and the smallest in winter, with an annual average of 5.3 mm Hg, which is the lowest area in Xing 'an League. The relative humidity is higher than other areas in the Union, with an average annual humidity of 70%. It is the largest in July and August every year, accounting for about 80%, about 50% in spring and 76%-79% in winter. Precipitation The average annual precipitation in Aershan City is 445.3mm, which is concentrated in July and August, accounting for about 47% of the whole year. The snowfall in winter is 36.8 mm, accounting for 6.7% of the annual precipitation, which is about 4.5% more than other areas in the Union. The precipitation variability is relatively stable, showing that it is large in spring and autumn and small in summer and winter. The air pressure in Aershan is mostly controlled by cold high pressure in winter, and the air pressure is high and low in winter at the intersection of spring and autumn, with an average of 898.3 hectopascals in June 5438+ 10 and 890.3 hectopascals in July, with an average of 895.3 hectopascals, which is about1000 hectopascals different from that in Baoan swamp area with the lowest altitude in Xing 'an League. Aershan has a temperate continental monsoon climate. In winter, it is influenced by northwest airflow, mainly by northwest wind and west wind; The spring and autumn seasons are influenced by the southeast monsoon, which mainly prevails in the southeast wind; The annual average wind speed is less than 2.7m/s, which is the lowest in Xing 'an League.