Characteristics of Temperature Variation in Shijiazhuang in Recent 46 Years

Based on the daily temperature observation data of 5 stations in Shijiazhuang during 1961-2006,the trends and characteristics of the daily mean temperature,the maximum and minimum daily temperature,the temperature daily range,as well as the hot and cool days were analyzed.The results show that the climate in Shijiazhuang had obviously warming trends in the recent 46 years,with the strongest warming trends in winter.Monthly temperature changes show that the most obvious amplitude was in February and the weakest was in May. Similar to the mean temperature,both the maximum and minimum temperature were in a rising trend as well.The rising trend of minimum temperature was clearer than the maximum and mean temperature.The strongest warming trend occur in the middle and the eastern part of Shijiazhuang.Temperature daily range was remarkably getting narrower in the recent 46 years.This was probably due to the greater increase in minimum temperature than maximum temperature.The cool days were decreasing but the change of hot days was not obvious.Hot days in the western,northern and southern part of Shijiazhuang show weak decreasing trend.