Abstract: This paper used the daily maximum temperature data of 80 meteorological observation stations in Jiangxi Province with complete observation data, and adopted the arithmetic mean method, linear trend method, significance test and other climate statistical diagnostic methods to select extreme maximum temperature, high temperature threshold days of different intensity and initial and terminal date of high temperature. The three high temperature characteristic indicators were used to analyze the variation characteristics of extreme high temperature in Jiangxi Province in the past 60 years and its impact on rice. The results showed that in the past 60 years, the annual number of days with the daily maximum temperature ≥35 ℃ in Jiangxi Province had increased significantly; the annual number of days with the daily maximum temperature ≥38 ℃ had not grown significantly;the annual cumulative station days with daily maximum temperature ≥40 ℃ did not change significantly from the 1960s to the 1990s, but increased sharply in the 21st century; the three high temperature threshold days of different intensities in most areas of Jiangxi Province all showed an upward trend; in the past 60 years, most areas of extreme maximum temperature in Jiangxi Province showed an upward trend, and most of the historical extreme values of the highest temperature occurred in the 21st century; the average first day of high temperature was significantly earlier, the average last day was obviously delayed, and the number of high temperature days increased significantly;high temperature had obvious effects on the heading, flowering, grain filling and milk maturity of double-cropping early rice and single-cropping rice in Jiangxi Province.

Key words: extreme high temperature, the beginning and end of high temperature, variation characteristics, rice, Jiangxi Province