Abstract:Based on the daily temperature data from 1951 to 2008 in Chongqing, the temporal variation of Heat Wave Duration Index (HWDI) and warm night index (TN90) are analyzed. Through evaluating the simulation capability of the IPCCAR4 Coupled Climate Model products, the results of HWDI and TN90 from 2001 to 2100 relative to the average of 1980 to 1999 in Chongqing, projected by the multimodel ensemble models under the A2, A1B, and B1 emission scenarios of SRES (Special Report on Emission Scenarios)are given. The results show that compared with the current climate (1980 to 1999), under the A2, A1B, and B1 emissions scenarios, HWDI and TN90 will increase sharply in the 21st century. During the period of 2011 to 2100, HWDI will increase by 77 to 123 days and TN90 increase by 122% to 164%. From 2011 to 2040, HWDI will increase by 31 to 41 days and TN90 increase by 57% to 7.3%. In the medium 21st century (2041 to 2070), HWDI will increase by 69 to 113 days and TN90 increase by 122% to 175%; in the latter 21st century (2071 to 2100), HWDI will increase by 124 to 216 days and TN90 increase by 171% to 278%.