Abstract:  According to the characteristics of summer high temperature in Xinjiang during 1961-2018, its spatial distribution could be divided into the whole-Xinjiang distribution pattern, north-south distribution pattern and west-east distribution pattern. For the whole-Xinjiang distribution pattern, the summer high temperature days increased sharply in the mid- and late-1990’s. For the north-south distribution pattern, the interconversion of more summer high temperature days and less ones was frequent in the 21st century. For the west-east distribution pattern, the summer high temperature days were more in the east but less in the west since the 21st century. The key zones of the circulation field, significantly correlated with the spatial distribution patterns, were all located in middle and low latitudes. According to the circulation analysis of Xinjiang summer high temperature days, when the South Asian high was strong and its central area was located northwards, the potential height at the middle and low latitudes in summer increased significantly, especially over the 30°-50°N zones, leading to an increase of summer high temperature days in Xinjiang. Strong South Asia high made the height of the middle latitude increase. In summer, the potential height over the 30°-50°N zones increased significantly, which was conducive to the increase of summer high temperature days in Xinjiang. The El Nino event is actually not conducive to the increase of summer high temperature days in Xinjiang.

Key words: high temperature, days, summer, El Nino event, the South Asia high; Xinjiang