Abstract: Based on gauged precipitation data from the China Meteorological Administration and NCEP/NCAR reanalysis data, this study investigates the circulation configuration and evolutionary characteristics of different types of extreme precipitation events using percentile analysis and K-means clustering, combined with atmospheric dynamic–thermodynamic diagnostics techniques. The results show that extreme precipitation in the Jianghuai region can be categorized into four types according to the location of the precipitation center: Central, Northern, Southern, and Eastern. The first three types mainly occur during the seasonal northward shift of the rain belt, whereas the fourth type is more scattered. During these events, the primary precipitation zones are located beneath the upper-tropospheric divergence region, positioned between the strong South Asian high and the westerly jet stream. These events are characterized by enhanced vertical velocity, intensified temperature gradients in the upper and middle troposphere, strengthened meridional circulation in the mid–high latitudes, an intensified subtropical high, and increased water vapor transport from oceanic regions. The first three precipitation types are different from the fourth in terms of East Asia–Pacific (EAP) teleconnection pattern, low-level jet, and water vapor transport. In the first three types, a typical EAP pattern and a pronounced low-level jet are observed, with water vapor mainly originating from the western Pacific and South China Sea. The upper-tropospheric temperature gradient exhibits a dipole anomaly, featuring colder temperatures to the north and warmer temperatures to the south. In contrast, for the Eastern-type events, a typical EAP persists, but no evident low-level jet develops. Water vapor transport occurs mainly as easterly flow along the East Asian coast, and only a unipolar warm center appears in the upper troposphere. The circulation pattern associated with low-frequency heavy precipitation resembles that of the Southern type, although the intensity and position of the South Asian pressure system, high-altitude westerly jet, subtropical high, low-level jet, and water vapor transport differ. The low-frequency evolution of thermodynamic conditions also varies among the four types. Central-type events occur during the northeastward movement of the subtropical high and the downward propagation of the EAP wave train. In Northern-type cases, the warm center of the near-surface temperature shifts southward from the Yangtze–Yellow River region to the area south of the Yangtze River, and the Jianghuai region exhibits a “cold above–warm below” thermal structure. Southern-type events occur during the southwestward movement of the subtropical high, with the 300 hPa temperature gradient reversing from “cold north–warm south” to “warm north–cold south,” and positive height values dominating the entire troposphere. Eastern-type events occur during the northeastward–southwestward oscillation of the subtropical high, accompanied by strengthening convective activity from low to middle latitudes, and almost entirely warm areas at 200 hPa and below. Further analysis demonstrates that variations in the subtropical high and associated thermal effects serve as key indicators of low-frequency prediction of extreme precipitation events in the Jianghuai region.