Geography of Zhenjiang District

Zhenjiang District is located in a subtropical area. In spring, cold air from the south and warm air from the north confront each other in South China. The district often experiences long-term low temperatures, accompanied by continuous rain and little sunshine. In early summer, under the influence of the western Pacific subtropical high pressure, the southwest monsoon brings abundant water vapor, resulting in relatively abundant rainfall in the region. In midsummer and early autumn, the regional environment is often affected by tropical depressions and typhoon circulation. In autumn, the northeast monsoon occupies the ground, while the subtropical high pressure still dominates the upper air, resulting in clear and dry weather, the best climate throughout the year. In winter, affected by the atmospheric circulation at low latitudes and restricted by the atmospheric circulation at mid- and high-latitudes, strong cold air moves southward, causing widespread cooling, strong winds and rainy weather in the region. After the cold front, the weather is generally sunny due to the control of cold high pressure. The regional climate characteristics are:

Short winter and long summer, rapid alternation between spring and autumn, and four distinct seasons. The district is divided into spring from March to April, summer from May to September, autumn from October to November, and winter from December to February of the following year. Spring alternates between cold and warm frequently, with low temperatures and rainy times. The average temperature is 15 to 20 degrees Celsius, and the average precipitation is about 300 to 400 mm. The summer is extremely hot, with the average monthly temperature ranging from 28.1 to 29.1 degrees Celsius, and the average maximum temperature ranging from 33.9 to 34.3 degrees Celsius. High temperatures above 35 degrees Celsius mostly occur in July and August. In midsummer, thunderstorms often occur in the afternoon due to the influence of typhoons, tropical depressions and circulation. Autumn is sunny and the temperature difference between day and night is large. As the cold air activity gradually intensifies and affects the regional environment, precipitation is also less. The impact of typhoons and cold air in autumn causes low temperature and rainy weather, commonly known as "cold dew wind", which is detrimental to the heading, flowering and grain filling of late rice. Winter is relatively cold, with frost occurring every year. In cold years, there are snowfalls and rain pine. The average minimum temperature is 5.2 to 7.1 degrees Celsius.

The sunshine is relatively abundant. The region is located at a low latitude, with relatively large solar radiation. The total annual solar radiation is 99-113 kcal/cm2. The seasonal coordination of light energy resources and temperature resources is good. The solar radiation time with the average daily temperature above 10 degrees Celsius accounts for 90% of the year. %, and mainly concentrated in the plant growing season, the water conditions are also more suitable, which is beneficial to the normal photosynthesis of plants.

There are many disastrous weather conditions. The climate conditions in the area are relatively superior, but there are also various climatic disasters such as heavy rain, drought, low temperature freezing, and hail. From February to March every year, there are often cold and rainy weather lasting for many days, with an average of 1.3 to 1.9 times per year, and the average number of days is about 10 to 14 days. Generally, "cold dew and wind" weather occurs in October, which is extremely detrimental to late rice production. Heavy rains mainly occur from May to June. When rainfall intensity is high, river water surges, accompanied by flash floods, endangering people's lives and property. The dry season mainly occurs from August to October, and the probability of drought is highest in September, which is called "autumn drought". It generally lasts 20 to 28 days, with the longest being 78 days. In addition, disastrous weather such as thunderstorms, strong winds, hail, and tornadoes generally occur from February to September.