Analysis on Characteristics of Changes in Hot Weather of Mainland China over the Past 57 Years

Based on temperature data of 740 stations in China in 1951-2007 and using statistical analysis method,this paper analyzed characteristics of changes in hot weather of mainland China over the past 57 years. Results showed that the change trend is not significant in north China. In the late 1980s,the temperaure rose obviously in north China,while it dropped sharply in southwest areas. In south of the Yangtze River valley,there was no great change after the 1960s and the temperature change was little in Qinghai-Tibet Plateau. In the early period of 1980s,the annual average maximum temperature of China had the lowest change. From then on,there was obvious temperature rise. In addition,change of extreme maximum temperature takes on significant regional difference,and there is high consistency in average change of temperature in south China and north China and regional difference in average maximum temperature. Both gradually rise from north to south. The northeast area is the highest in the difference between the extreme maximum temperature and average maximum temperature and between the extreme maximum temperature and average temperature,followed by northwest area,and the lowest is southwest area. Qinghai-Tibet Plateau is the highest in the difference between average maximum temperature and the average temperature,followed by middle and lower reaches of Yangtze River,and the lowest is south China.