What are the climatic conditions for agricultural production in Shanwei City?
Shanwei has a warm climate, with an annual average temperature of 21 ~ 22℃, an annual average maximum temperature of about 26℃, an annual average minimum temperature of about 19℃, and a safe rice growing period of about 26 days. There is abundant rainfall in the territory, with the average annual rainfall of 18～24mm for many years, and the annual rainfall in the most years can reach 3728 mm. The same season of rain and heat is one of the climatic characteristics of Shanwei city. The rainy season starts from late March to early April and ends in mid-October. The flood season from April to September every year is the season with the most heat and the most concentrated rainfall, accounting for about 85% of the total annual rainfall. The city has plenty of sunshine. The average annual sunshine hours for many years are 19-21 hours, the sunshine percentage is 44-48%, the annual average total solar radiation is more than 12 kcal/cm2, and the photosynthetic potential is about 74kg per 1/15 hectare.
"winter is not cold, summer is not hot, summer is long and winter is short, and spring is early and autumn is late" is also one of the main climate characteristics of Shanwei city. The average temperature in Leng Yue in January is about 14℃, the average number of days with low temperature of ≤5℃ is 2.9 days, the average number of days with low temperature of ≤2℃ is .1 ~ .3 days, and the extreme minimum temperature is only-.1℃. In the hottest month, the average temperature in July is about 28℃, the average number of days with high temperature of ≥35℃ is .7 ~ 1.5 days, and the extreme maximum temperature is only 38.8℃, which is worthy of the name that winter is not cold and summer is not hot. According to statistics, the summer in Shanwei is about 183 days, while the winter is only about 1 days, which is really long in summer and short in winter. In China, spring is early and autumn is late, and early spring has already arrived in early February, but it has not arrived until the end of October.
Because the average rainfall from October to March in autumn, winter and spring only accounts for about 15% of the annual rainfall, continuous droughts in autumn, winter and spring occur from time to time. In addition, due to the influence of topography and long coastline, Shanwei City is not only one of the three major rainstorm centers in Guangdong Province, but also one of the areas affected by tropical cyclones, so summer waterlogging is the most important meteorological disaster in Shanwei City. According to statistics, the average number of rainstorm days in Shanwei city for many years is about 12 days, up to 23 days; In addition, the average number of tropical cyclones affecting Shanwei city is 4.5 for many years; The average number of tropical cyclones with serious influence is .8 for many years; The average number of tropical cyclones landing in Shanwei city for many years is .5. The average initial date of reaching the impact standard for many years is July 4th, with the earliest appearance on May 1st (1999) and the latest appearance on August 14th (1975). For many years, the average day is September 22nd, with the earliest appearance on July 1th (1955) and the latest appearance on December 2nd (1974). Violent winds, heavy rains and tidal waves brought by tropical cyclones often lead to wind, flood and tidal disasters, but its abundant precipitation can alleviate drought, increase reservoir water storage, and reserve rich water sources for the production of early rice and other crops in the following year.