The geographical environment of Huaining County
Huaining County belongs to the northern subtropical humid monsoon climate zone, with four distinct seasons, mild climate, abundant rainfall, sufficient sunlight, and short frost and snow periods.
The beginning and end of spring are March 16 and May 20 respectively, lasting 66 days. Warming up is faster, but cold and warm air currents alternate frequently, and late-spring cold weather often occurs. The seasonal average temperature is 15.9℃, the extreme maximum temperature is 34.3℃ (May 20, 1980), and the extreme minimum temperature is -0.4℃ (March 20, 1976), with a range of about 35℃. The wind direction is variable during this season, but is often dominated by northeasterly winds. There are an average of 11 rainy days per month throughout the year, and an average of 15 rainy days per month during this season.
The beginning and end of summer are May 21st and September 25th each year, lasting 128 days. From late May to late June, it is the Mengxia Meiyu period. Plum blossoms usually start in mid-June and emerge in mid-July. During this period, rainfall is concentrated, with heavy rains and heavy rains, and floods occur from time to time. High humidity makes clothes and food prone to mold. The period from early July to early August is the midsummer period, which is often controlled by subtropical high pressure. It is sunny and hot weather, with local thundershowers. The temperature is high, the sunshine is strong, and the evaporation is large. It is the driest and hottest period of the year. From mid-August to late September, it is the end of summer and is sometimes affected by typhoons, accompanied by rainfall processes of varying intensity and strong winds.
The beginning and end of autumn are September 26 and November 20 each year, lasting 56 days. Autumn is characterized by crisp air, large temperature difference between day and night, little rain and the beginning of fog. As the influence of cold air from the north gradually becomes apparent, the temperature slowly drops and becomes colder by the end of the season, with occasional frost and snow.
The beginning and end of winter are November 21 of each year and March 15 of the following year respectively, lasting 115 days. After light snowfall, winter begins, with north to northeasterly winds prevailing. The seasonal average wind speed is 3.3 meters/second, and the maximum wind speed is 20 meters/second. Due to the strong cold air from the north frequently moving southward, the temperature drops sharply, and the weather is mostly sunny and cold. The seasonal average temperature is 4.6℃, the extreme minimum temperature is -15℃, and the average number of days with multi-year daily minimum temperature ≤0℃ is about 41 days.