Based on hourly precipitation data at 146 automatic weather stations of Lanzhou from 2012 to 2019, the refined characteristics of precipitation in Lanzhou were analyzed from different time scales. The results are as follows: (1) The average annual precipitation was less in the north and more in the south of Lanzhou, and that was more in the edge and less in the interior from 2012 to 2019. The inter-annual change of precipitation was obvious from 2012 to 2019, the precipitation in 2018 was abnormally more by 46%, while that in 2015 and 2017 was abnormally less, especially in 2015 it was less by 30%. (2) The precipitation mainly concentrated in July and August in Lanzhou, and it in the south was obviously more than that in the north due to the influence of atmospheric circulation situations, while the spatial difference of precipitation wasn’t obvious in other months. (3) The diurnal variation of rainfall was obvious in Lanzhou, the precipitation was less in morning and more at night, and the range of rainfall was larger at night and smaller in the daytime. The precipitation in urban areas was generally less than that in mountain areas under the influence of altitude, and it mostly concentrated from afternoon to evening due to heat island effect, the convective rainfall was more, while the diurnal distribution of rainfall was more uniform in mountain areas, the fluctuation was smaller as a whole. (4) Overall, the frequency of short-time heavy rainfall in Anning district of Lanzhou was the highest, but the short-time heavy rainfall at Liuhe station of Gaolan county and Xujiamo station of Yongdeng county was the most frequent, and that in Yongdeng county was a critical concern.

Based on the daily mean air temperature data of NCEP/NCAR during 1948-2017, the extreme high temperature events in Central Asia were determined by percentile threshold method, then the temporal-spatial distribution characteristics of intensity and frequency of extreme high temperature events over the past 70 years were analyzed. The results show that the spatial distribution of mean temperature in warm season in Central Asia was significantly affected by topography, and it gradually decreased from southwest to northeast. The intensity and frequency of extreme high temperature events occurred interdecadal transition in 1967. The intensity after transition was significantly higher than that before the transition. The frequency showed a negative trend before 1967 and a positive trend after that. The areas of extreme high temperature events also occurred interdecadal transition. According to the trend distribution of intensity, the region with the most significant increase was located in the west of Uzbekistan, and the region with the most significant negative trend was located in the southern Xinjiang of China. While the most significant increase in frequency trend was in Ural region of western Kazakhstan, and the negative trend was in Pamir Plateau.