Based on the daily air temperature data of 13 meteorological stations in Hetao area from 1960 to 2013, using the methods of linear fitting, accumulative anomaly, Mann-Kendall test, principal component analysis, Morlet complex wavelet, and R/S analysis, we calculated and studied 10 kinds of extreme air temperature indices released by WMO.The results were obtained as follows: in Hetao area in recent 54 years, the average air temperature, extreme maximum air temperature, extreme minimum air temperature, and heat indices (summer day, heat night, warm day, and warm night) all showed an increasing trend, while the cold indices (ice day, frost day, cold day, and cold night) all decreased significantly.The changes in extreme air temperature indices in Hetao area had obvious spatial distribution characteristics and sudden change phenomenon, and the sudden changes occurred mainly in the 1980s and 1990s.The rising of both heat indices and winter air temperature was the main reason for the increase in annual average air temperature in Hetao area.The extreme high temperature events happened for many times in the later 1990s and the beginning of the 21st century, and occurred mostly in July (especially in the middle of July).AO and NAO indexes had significant influences on the extreme air temperature indices in winter and spring (especially in winter) in Hetao area.%根据1960~2013年河套地区13个站点的每日气象资料,应用线性拟合及累积距平、Mann-Kendall突变检验法、主成分分析法、Morlet复数小波和R/S分析等方法对WMO发布的10种极端气温指数进行了计算和研究.结果表明:在近54年里,河套地区平均气温、极端最高气温、极端最低气温和热指数(夏日、热夜、暖日和暖夜)均呈现上升趋势,冷指数(冰日、霜日、冷日和冷夜)均显著减少;河套地区极端气温指数的变化具有明显的空间分布特征,并伴有突变现象,突变发生在20世纪80和90年代;暖指数的上升和冬季气温升高是河套地区全年平均气温上升的主要原因;极端高温事件在20世纪90年代后期和21世纪初发生的次数较多,在全年各月中以7月份发生次数最多,尤其是7月中旬;AO与NAO指数对河套地区冬春季(尤其是冬季)极端气温指数具有显著的影响.
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