The spatial-temporal changes of human comfort in main capital cities in China from 1951 to 2008

Based on the meteorology data of the main capital cities in China from 1951 to 2008, average temperature and wind effect index (K) were calculated and by means of linear regression, Spearmen´s rank correlation and change rate, the tendency of temperature and wind effect index were analyzed by year, season and spatial. The results showed that in recent 58 years, the average annual temperature of the main capital cities showed an obvious upward trend with the speed of 0.3 centigrade per ten years. And the rising tendency in north of China was most obvious with the speed of 0.47 centigrade per ten years. In addition, the average of annual wind effect index (K) also revealed the same tendency with the speed of 10.8 per ten years. And with the speed of 20.6 per ten years, wind effect index increased most rapidly in northeast of China. During different season wind effect index (K) showed varying range of variation, which meant the range of change was biggest in winter while smallest in summer. The spatial distribution revealed that wind effect index (K) was higher in South of China, while lower in North of China all the year round.