Winter Temperature Characteristics of Nanjing During 1951—2006

Based on the daily temperature data during January 1951 to April 2007 in Nanjing, the change trends andcharacteristics of winter average temperature, annual extreme-low temperature, cold accumulated temperatureand low temperature days in Nanjing in the recent 56 years are analyzed and studied.The annual change of thewinter temperature and the distribution of warm winter and cold winter are discussed.The results show that theannual mean temperature tends to rise in the recent 56 years, and that winter average temperature also tends torise obviously as well as the winter lowest temperature and cold accumulated temperature tends to rise even moreremarkably.In recent 56 years, the average temperatures in November and December have no obvious change, at the same time the rising tendency of average temperature in January, February and March is very remarkable.The rise of temperature in winter is mainly contributed to by the rise of temperature in January, February andMarch, and that in November and December is slight.The obvious rise of winter temperature in recent 56 yearsis in accord with the global warming.The winters of 1950s and 1960s in Nanjing are low temperature periods, and the winter temperature tends to rise after 1970s.The phenomena of cold winter are all before 1980s, theydon't appear again till after 1990s.The phenomena of warm winter are very frequently observed after 1990s, and they appear once every two years.The winter temperature in Nanjing tends to rise more obviously after1980s, and the extraordinary phenomena of warm winter sustain after 1990s in Nanjing.The phenomenon ofbeing unusual warm in winter is more conspicuous in early several years in the 21st century.