Geographical environment of Xiaonan District

Xiaonan District has a subtropical monsoon climate, with an average annual temperature of 16.2℃, an average annual precipitation of 1,146 mm and an average annual sunshine hours of 2,25 hours.

Climatic characteristics of the four seasons: In spring, cold air often goes south, which causes the temperature to rise and fall sharply and changes greatly, and sometimes cold waves occur; The alternate seasons of late spring and early summer have mild climate and abundant rainfall; Summer is hot and sweltering for a long time, with "plum rain" from late June to early July. At this time, it is prone to heavy rain, causing floods and waterlogging, with southerly winds, and forming a "Nanyang" wind with high wind speed during the day and low wind speed at night. Squall lines also occur in this season. Autumn is crisp and sunny in normal years, with "cold dew wind" in early autumn and a mild "Xiaoyangchun" weather in late autumn; Winter is cold and rainy, with northerly winds and long frost time.

temperature: the annual average temperature in the whole region is 16.2℃, and the annual variation characteristics of the average temperature show a single peak shape, with the coldest in January and the extreme minimum temperature reaching-14.9℃; It is the hottest from mid-late July to early August, with an extreme maximum temperature of 38.5℃. The general characteristics of daily variation of temperature are: the highest value appears around 2 pm, the lowest value appears around sunrise in the morning, and the temperature difference between day and night is 7-1℃.

sunshine: xiaonan district is rich in sunshine resources, and the annual sunshine hours are 4,427.6 hours, with an average of 1.1-14.1 hours per day. Due to the cover of clouds, fog and rain, the annual average actual sunshine hours in the whole region are 225 hours, and the sunshine percentage is 45.7%.

precipitation: the annual average precipitation in the whole region is 1146 mm, and the monthly distribution of precipitation is the highest in July and the lowest in December, showing a single peak type.

frost-free period: the average number of frost-free days in the whole year is 245, accounting for 67.1% of the total number of days in the whole year. The shortest frost-free period is 193 days and the longest is 286 days. Over the years, the first frost day appeared on October 26th, the latest on December 3rd, and the average appeared around November 16th. The last frost day appeared on February 19th at the earliest, and on April 15th at the latest, around March 12th on average.

there is low temperature and rainy weather in spring; There is "plum rain" in early summer, high temperature and drought in midsummer, and heavy rain often causes floods and waterlogging; There is a "cold dew wind" in early autumn, drought or continuous rain; There are ice hazards in winter. In addition, there are local hail, gale, tornado, thunderstorm and other disasters.