Weather & Climate
Situated in the mid-latitudes, Haimen has the north subtropical southern sub-humid monsoon climate, monsoon circulation is to blame for the inland climate. Owing to the solar radiation, atmospheric circulation and a specific geographical location, Haimen climate is characterized by: Mild climate, 4 distinct seasons, ample rainfall and integrated rainfall, hot rainy season, cold in winter and hot in summer and spring temperature variability, crisp autumn, abundant sunshine and rich in heat.
The excellent climate resources have provided favorable conditions for industrial and agricultural development. However, Haimen is a typical climate disaster prone area, because of the location in the mid-latitudes, land and sea in transition zone and the climate transition zone. Common climate disasters are floods, droughts, rainy season, heavy rain, tropical cyclones, continuous rain, extreme heat, hail and tornado, rare cold, frost, intensive fog and so on.
Haimen has the annual mean temperature 15.2 degrees C, cold in winter and hot in summer, with January as the coldest month for the whole year, the extreme coldest month fell in January 1963, monthly mean temperature 0.0 degrees C; and July as the hottest month for the whole year, the extreme hot month fell in July 1971, with monthly mean temperature 29.9 Degrees C.
Extreme minimum temperatures come often in January and February when the cold air from north continuously invade southward. Since 1959 when we first had records of temperature, Haimen's extreme minimum temperature of -9.3C appeared in January 31, 1977, and Haimen's extreme maximum temperature of 39.7C, appeared in August 8, 2013.
The average annual precipitation 041.7mm, with an annual maximum precipitation 498.3mm (1975), the minimum precipitation 650.9mm (1978). The summer rainfall often results from the rainy season, typhoons and local geographical lightning weather, with integrated intensive precipitation. Flood disasters occurred more often, due to the large volume of runoff into rivers and low-lying areas. Spring and autumn precipitation are relatively less than in summer, and still less in winter. There are abrupt variations in the amount of rainfall from year to year, and the character of precipitation assumes continuous drought and flood.