The variation of urban heat island (UHI) effect in Jining of Shandong province was analyzed using meteorological measurements such as mean air temperature,mean wind speed,precipitation,cloud cover and visibility data from Jining,Yanzhou,Jiaxiang and Wenshang station at 02:00,08:00,14:00,and 20:00 BST from 1981 to 2013.Results show that the UHI effect in Jining has obvious monthly and diurnal variation characteristics.The UHI effect was stronger in the winter half year than in the summer half year;significantly weaker in daytime than in nighttime,and the weakest at noon.As for seasonal variation,the UHI effect in Jining is strongest in winter and weakest in summer,and in a slowly growing trend in seasons of spring,summer and winter.The UHI effect varies greatly under different weather conditions,which is most obvious at sunny windless weather with average value of 0.79 ℃,and least obvious at rainy weather with average value of 0.09 ℃.Fog and wind with speed equal to or greater than 4.0 m/s mostly occur in autumn or winter,but fog effects greater than wind on the formation and diurnal variation of UHI.As for the diurnal variation,the UHI effect is strongest at different time of a day under different weather conditions,which occurs at 02:00,20:00,and 08:00 at sunny windless foggy weather,precipitation weather,and strong windy weather conditions,respectively;while the UHI effect is weakest at 14:00 under all weather conditions.