Based on hourly precipitation data from 183 national meteorological stations from 1983 to 2018, this study employs methods such as the iterative Mann-Kendall trend test, Spearman’s rank correlation analysis, and wavelet analysis to examine the spatiotemporal evolution of extreme precipitation and its relationship with atmospheric circulation patterns in the Huang-Huai-Hai Plain and Jiang-Huai Plain. The analysis focuses on two dimensions:precipitation events and subdaily extreme precipitation indices. The results show that summer precipitation events in these regions are characterized by short durations, high frequencies, and intense rainfall, with spatial variations in precipitation patterns. Except for moderate-intensity precipitation hours, more than half of the stations exhibit an increasing trend in the frequency, intensity, and duration of extreme precipitation. Compared to the period from 1983 to 1999, the first two decades of 21 century saw a significant rise in the frequency, intensity, and duration of extreme precipitation, although the increase in average precipitation intensity was not significant. The Atlantic multidecadal oscillation shows the strongest teleconnection with extreme precipitation index in the Huang-Huai-Hai Plain and Jiang-Huai Plain, with dominant 6-10 month coherent spectral bands for both intensity and frequency indices.