Based on daily and hourly precipitation data collected at 33 meteorological observational stations in Beijing-Tianjin-Hebei during 1970-2015, spatial and temporal characteristics of midsummer (July and August) and early Autumn (September) precipitation are analyzed. It is found that the midsummer precipitation decreases significantly during the past 46 years, and the midsummer shifts from rainy phase to rainless phase at the end of the 1990s. From the point of view of diurnal precipitation variation, accumulated precipitation at any intervals and individual hours of the day has been decreasing since the late 1990s. Decreases in long-duration precipitation make more contribution to the decreasing trend of total midsummer precipitation. On the other hand, precipitation in early autumn exhibits an increasing trend, and early autumn shifts from rainless phase to rainy phase at the beginning of the 2000s. There is an obvious increase of nocturnal precipitation during the recent decade. And increases in long-duration precipitation are largely responsible for the phase shift and increases in total precipitation in early autumn. Further analysis reveals that monthly mean daily maximum temperature shifts from low-temperature phase to high-temperature phase at 1997, accordingly, short-duration precipitation shifts from rainy phase to rainless phase in the midsummer. Note that monthly mean daily maximum temperature and short-duration precipitation in early autumn show no obvious trend. Also, it is found that the retreat of the East Asian summer monsoon delays during late summer and early autumn, leading to the phenomenon of delays of midsummer precipitation until early autumn in Beijing-Tianjin-Hebei. The results show that the blocking high has intensified over the mid-high latitudes of Eurasia in the midsummer since early 2000s, resulting in less water vapor transport by the mid-latitude westerly jet to Beijing-Tianjin-Hebei. Meanwhile, the East Asian jet shifts southward while the ascending motions over Beijing-Tianjin-Hebei become weak. The above circulation patterns lead to less precipitation in the midsummer. In contrast, more water vapor can be transported to Beijing-Tianjin-Hebei in early autumn due to the northward shift of the East Asia jet and intensified ascending motions over Beijing-Tianjin-Hebei since early 2000s. Meridional circulation also strengthens since the low trough in Lake Baikal is blocked by the high pressure system to its east, which is in favor of cold air activities. Meanwhile, the western Pacific subtropical high intensifies and shifts further north. The above circulation changes lead to more precipitation in early autumn in Beijing-Tianjin-Hebei. Besides, the index of land-sea thermal difference shows a significant increasing trend in early autumn, which may reflects a delayed southward retreat of the East Asian summer monsoon.