What are the main characteristics of temperature and precipitation in Changsha?

Changsha's climate features are: Leng Xia is hot in winter, with four distinct seasons; Spring and autumn are short, winter and summer are long, which fully embodies the similarities and differences of subtropical continental monsoon climate types.

Spring: The climate is characterized by rapid warming and large temperature changes. This is a well-known proverb in Changsha. From the average temperature of 10℃ in March to 22℃ in May, the temperature rose by 12℃ in just two months, with an average monthly increase of 6-7℃. At the same time, the temperature not only rises rapidly, but also changes greatly. The lowest monthly average temperature is 13.6℃ and the highest is 2 1. 1℃, with a difference of nearly 8℃. Another example is 1969, where the lowest temperature was 2.5℃ on April 5, while the highest temperature was 33.4℃ on April 10 of the same year, and the five-day temperature difference exceeded 30. However, the large temperature difference has brought adverse effects. The second feature of Changsha in spring is continuous rain and humid air. The average rainy days in Changsha from March to May (the daily rainfall is equal to or greater than 0. 1 mm) is 52.8 days, accounting for more than 35% of the total rainy days in a year (15 1.2 days), and continuous rainfall still occurs for many years. Therefore, the precipitation from March to May accounts for more than 40% of the total annual precipitation. The cloudy days in these three months (the daily average total cloud amount is more than 80%) account for more than 365,438+0% of the total cloudy days in the whole year, and the relative humidity is between 83% and 84%, which is the season with the highest relative temperature in the whole year. In short, Changsha's spring rain is famous all over the country. Summer: Everyone knows the long summer heat in Changsha, which lasts for four and a half months. This is the longest season and the highest temperature in a year. From June to September, the ten-day average temperature is 25℃, and from late July to late August, the ten-day average temperature is above 29℃. According to the records, on August 1934, the highest temperature measured at the observation point of Tianxin Park in Changsha Customs Waiting Station was 43℃. It is the limit of high temperature in Changsha. The highest temperature since 1949 is 40.6℃, which was measured on 1953 in August. This situation is relatively rare in China. The average daily temperature in Changsha is higher than 30℃ for 94 days in a year, including 84 days in summer, and it is higher than 35℃ for as many as one month in a year, which is basically concentrated in. The relative temperature is relatively high, which makes summer steaming. Therefore, Changsha, Chongqing, Wuhan and Nanjing are also called the four furnaces in Changsha Basin. Another feature of Changsha in summer is uneven precipitation and uncertain drought and flood. The rainstorm days in Changsha are mostly concentrated in May, June and July, from 195 1 to 1980. In Changsha, May 23rd, June 29th and July 20th accounted for more than 65% of the total rainstorm. However, the rainfall varies greatly from year to year. For example, the total average precipitation in late June was 69.8 mm, but 1969 was as high as 384.8 mm, while 1975 did not rain. For example, the precipitation in early July was 465438. It hasn't rained for five years. Uneven precipitation will inevitably lead to floods or droughts. However, due to high temperature and rainy weather, summer in Changsha still provides favorable climatic conditions for crop growth. Autumn: Autumn in Changsha is a rainy season. According to statistics, the average precipitation from late September to165438+1mid-October was only 23.6 mm, and there was no rain for nearly 40 days for many years in history, and the characteristics of autumn dryness were very obvious. In addition, although autumn in Changsha is short, there are many sunny days. According to statistics, the number of sunny days with annual average low cloud cover less than 2 in Changsha is *** 136.2 days, while from September to 1 1.5 days. From hot summer to cool autumn, but the temperature is slightly higher than that in spring, so Changsha enjoys the reputation of "October Spring". The "golden autumn season" in Changsha not only has picturesque scenery of "the mountains are all red and the forests are all dyed", but also has bleak winter scenery of "thousands of trees are steamed with frost dew, the waves surround the wind and shake a continent" and "jellyfish look at Miao Shuo everywhere, and huts refer to wheat autumn". Winter: There is no severe cold in Changsha in winter, and there is little rainfall. The average monthly temperature in winter is mostly above 5℃, and the average monthly temperature in the coldest month 1.6℃ is also 1.6℃, with a maximum of 8.6℃. Frost or freezing weather occurs when the temperature is lower than 0℃ in one day, and the average winter is only 19.9 days. For example, on February 9th 1972, the lowest temperature reached-1.3℃,1October 9th1969,65438+31,reaching -9.5℃. When the daily average temperature is -5℃, the annual average is only 1.3. In the month of 65438+February with the least precipitation, the monthly average rainfall is 45.3 mm, which is more than that in Nanjing (29.4 mm) in the lower reaches of the Yangtze River and Guangzhou (24.7 mm) in the Pearl River Delta. This rainfall is enough for the growth of overwintering crops. Because the rainfall is moderate and not very cold, the winter in Changsha is not bleak, and evergreen broad-leaved trees such as Cinnamomum camphora and Ligustrum lucidum are still lush. As Du Xunhe said in the poem "Boating on Xiangjiang River with Friends in Late Winter" in the Tang Dynasty: "Where is the residual wax boating? Xiaoxiang is the most popular place. " Changsha's climate, with four distinct seasons, includes both the exuberance of life and the struggle against nature. The ups and downs of the environment have cultivated Changsha people's pepper character and fighting spirit. Since human beings appeared in this land, it has lasted for thousands of years and is still flourishing today.