| Based on the daily temperature observation data of 17 stations in Shijiazhuang area during 1972～2008,which had been tested and homogeneity-adjusted, and the statistical methods, the trends and decadal variation features of the daily mean temperature, the maximum and minimum daily temperature, the temperature daily range, the hot and cool days, as well as the frost and frozen days were analyzed. Applying the average temperature observation data of the Shijiazhuang city during 1955-2008,the periodical features and urban climatic characteristics of the temperature of the city station was also analyzed. The analysis results show that the climate in Shijiazhuang had an obvious warming trends during recent 37 years, with the warming phenomenon of minimum temperature more significant, and the strongest warming trend occurring in winter and the weakest warming trend in summer. Daily temperature range (DTR) was getting smaller in recent 37 years, with the strongest drop being in spring and the weakest drop in autumn. This was induced probably by the greater increase in minimum temperature than maximum temperature. Hot days tended to increase, and cold days, frost days and frozen days tended to decrease, indicating a more moderate temperature condition in the region. The annual mean temperature in Shijiazhuang station had a significant cycle of about 7.2 years.This paper also analyzes precipitation variation in Shijiazhuang during 1972～2008 by using the daily precipitation data of 17 stations. The results show that during recent 37 years, the annual mean precipitation in Shijiazhuang experienced an decreasing trend, but the trend is weak and insignificant. Precipitation in spring and fall had an increasing trend, with the trends in spring being significant; Precipitation in summer and winter had an insignificant downward trend. Precipitation in Shijiazhuang area had obvious seasonal variations and regional differences. The annual precipitation in Shijiazhuang area in 1970s-1990s basically reduced from west to east, while in 2010s the pattern changed to a reduction from northwest to southeast. The annual precipitation in Shijiazhuang station had cycles of about 4 years,6-7 years and 26 years.The number of rainstorms in Shijiazhuang in the past 37 years experienced a slight increase. The numbers of heavy rainfall events in June, August, September (flood season) showed an insignificant upward trend in Shijiazhuang, with the linear trend in June being the largest; and the linear trend in July the smallest. The numbers of heavy rainfall events in the earlier, mid and later periods of June and August all showed an increasing trend, with the increasing trend in late June being the most significant. The numbers of heavy rainfall events in the earlier, mid and later periods of July showed a decreasing trend, with the decreasing trend in late July being significant. The numbers of heavy rainfall events in the west and north of Shijiazhuang area increased, and the increasing trend in Xinle in north was significant. The south and a few places of the east and northwest witnessed a declining trend, and the declining trend was generally significant. The numbers of heavy rainfall events in Shijiazhuang station had cycles of about 18 years,7.2 years and 2.77 years.Based on the daily mean temperature, minimum and maximum temperature data of the urban station of Shijiazhuang city and four rural stations of Gaocheng, Yuanshi, Pingshan and Xinle during 1962～2009, the city climate characteristics and trend of urban heat island (UHI) effect at Shijiazhuang station have been analyzed. The urbanization effect on the long-term precipitation change was also analyzed. The results show that the UHI effect on air temperature change at Shijiazhuang station was very significant, with the effect on the minimum temperature trend being even more significant. The UHI intensity at the station had a significant increasing trend. The UHI intensity at the station was the strongest in winter and it was the weakest in summer. The UHI intensity at Shijiazhuang station showed significant increasing trends for all of the seasons and months. It is also found that the UHI intensity at Shijiazhuang station had a significant diurnal variation, and it was stronger in the night than in the day. The urbanization effect on temperature trends of the city station is becoming more significant with time. The increasing rate of the UHI at Shijiazhuang station in the 37 years was 0.26℃/10a, and the contribution rate of the UHI change to the overall annual warming was estimated to be 45.6%. More significant increasing rate of the UHI magnitude at the station was found for autumn and winter.However, the urbanization effect on annual mean precipitation change of the city station was found to be small. The change rate of annual precipitation due to the urbanization at Shijiazhuang station was only 0.3mm/10a, and the difference between the urban and suburban stations was not significant. The urbanization effect on the linear trends of summer precipitation and winter snowfall were more obvious than those of spring and autumn rainfall.
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