Climatic characteristics of Dongshao Township in Ningdu

Ningdu County is located at 26 05'18 "north latitude to 27 08'13" east longitude to15 40' 20 "to1617' 65438. Mid-subtropical monsoon humid climate zone. The climate is mild, the four seasons are distinct, the sunshine is abundant, the rainfall is abundant, there is no severe cold in winter and the frost-free period is long, which is suitable for the normal growth of subtropical crops.

Four seasons change

Winter165438+1from late October to early February 65438+In winter, Ningdu is located in the southeast of the cold high in Mongolia, so the north wind or northeast wind often blows. During this period, there was a cold wave accompanied by frost, snow and freezing weather. Normal years are: the previous winter was cold, sunny, frosty and dry; It is rainy and snowy after winter, and the weather is cloudy and cold. As the saying goes, "39, 49, don't shoot when you meet." He also said: "Great cold, slight cold, dripping into a ball." 1From mid-October to mid-February, it is the coldest season in the whole year, during which heavy snow and freezing rain mostly occur.

In the middle and late March of spring, the intensity of cold high in Mongolia gradually weakened, and the Pacific subtropical high gradually approached the county. The temperature rose and the rain increased, which was called "continuous spring rain" and "no sunny day in spring". However, the early temperature is still low, often affected by strong cold air, and sometimes the weather is cold. As the saying goes, "The tiger froze to death in Qingming Grain Rain". In the later period, the north-south air mass moved towards each other in the county. The precipitation is strongly concentrated, and there are often heavy rains, which makes the river water level rise sharply and flash floods. This is the flood season in Ningdu, and there are often thunderstorms or hail.

It enters summer in late May and enters midsummer after the flood season. Controlled by the Pacific subtropical high, the weather is hot. Because it is located at the northern edge of high pressure, it often blows south wind or southwest wind. There is a saying called "Xiao Nanfeng 18 days." When the subtropical high is strengthened or weakened, it is easy to form hot thunderstorm weather. This kind of thermal thunderstorm mostly occurs in the afternoon or evening, and its locality is obvious. There is a saying that "summer rain blocks the wall, and women don't shower their mothers." During this period, typhoons often affected the county, with precipitation, cooling, strong winds and heavy rain.

Autumn came in late September, and the summer monsoon weakened, but the temperature was still high, commonly known as "autumn tiger". However, the heat is different at this time. The so-called "the millennium equinox, the night is cold and the day is hot". It is hot during the day, but it turns cold at night, and autumn is getting stronger. During this period, the ground is controlled by cold high pressure to the middle and low altitude, and the middle and high altitude is still affected by warm high pressure. It is high pressure from the ground to the sky, and it is warm and cold, and the gas layer is stable, so it is not easy to form clouds and rain, and the weather is sunny in most years. There is "Xiaoyangchun" weather in late autumn, which promotes the flowering and even fruiting of plants.

Temperature and frost conditions

The annual average temperature is between 14 and 19℃. The mountains in the north are very low, and the hills and valleys in the south are very high. Meijiang Basin and Gucun Basin in Huangshi and Laicun are two areas with higher average temperatures, both above 65438 09℃. The average annual temperature in Ji Lang is only 65438 04℃ in the northern days. Extreme temperatures are also high in the south and low in the north. The extreme maximum temperature has a small difference between north and south, while the extreme minimum temperature has a big difference.

The monthly average temperature is lower than 10℃ from February to February, and the lowest temperature is 1 month. Since March, the average temperature has been above 10℃ for nine consecutive months, with the highest temperature in July.

According to the stable passage from 10 to 20℃ in this county, the start and end date of 80% assurance rate: 10℃ first appeared on March 25th, and 20℃ finally appeared on September 28th, which lasted for 187 days, with a total accumulated temperature of 4723.5℃.

Precipitation The annual precipitation is between 1500 and 1700 mm. Generally speaking, there are more in the north, less in the south, more in the east and less in the west.

The precipitation from April to June accounts for 40~70% of the annual precipitation, with a large proportion.

If it exceeds 30% of the average annual precipitation from April to June, it will be designated as a particularly wet year. From 1939, there are six years of catastrophic floods, namely 1944, 1954, 1959, 1962 and 1968. There have been great floods in these years.

If it is less than 30% of the average annual precipitation from April to June, it is designated as a dry year. There are five dry years from 1939: 1940, 1943, 195 1, 1963,197/kloc-. Serious droughts have occurred in these years.

Compared with the precipitation in April-June, the precipitation in July-September is obviously reduced. During this period, it is easy to form summer and autumn drought.

The precipitation is the least from 10 to 12. 1-The precipitation in March is second to that in July-September.

The annual average precipitation is 1.706 mm, the maximum value is 1.997, reaching 279 1 mm, and the minimum value is in 2003. The ratio of annual average precipitation days to years without precipitation days is 18: 20, with little difference. An agricultural proverb says, "As many sunny days as there are rainy days". Since 1939, the maximum daily rainfall is 1 959 June 18 and1984 June1,both of which are 2 18. 1 mm.

Sunshine: average sunshine for many years 1938.8 hours, sunshine percentage of 44%, annual average total solar radiation 1 12 189.9 calories /cm2.

Frost-free period: the average frost-free period in the county is 279 days. The longest is 3 19 days, and the shortest is 224 days.

The average first frost date is165438+1October 30th. The earliest frost date is 1 1.5, and the latest is 1.3 the following year.

The average final frost date is February 22nd. The earliest final frost date is 65438+1October 16, and the latest is March 28th.

The interval between the first frost and the last frost (frost date) is 85 days on average for many years. The longest is 128 days and the shortest is 32 days.

The first frost is early and the last frost is late in the northern part of the county. The frost period is longer than that in the south and the frost-free period is shorter than that in the south. According to the observation records of the county meteorological bureau, there is less frost at the top of the mountain and more frost in the intermountain basin. As the saying goes, "the snow is high and the mountains are frosty."