Abstract: To understand the weather characteristics of extreme short-duration heavy rainfall (EHR, defined as hourly rainfall ≥50 mm) in Northeast China, this study utilizes meteorological observation station observations and ERA5 reanalysis data from 2017 to 2024. By employing a subjective synoptic classification, EHR events are classified into five categories to comparatively analyze their spatiotemporal distributions and environmental characteristics under different synoptic patterns. The results are as follows. The frequency of EHR occurrences in Northeast China decreases in the following order: cold vortex, Western Pacific Subtropical High (WPSH) periphery, westerly trough, typhoon, and weak-synoptic forcing type. Compared to other EHR types, the cold vortex-type EHR exhibits stronger rainfall intensity, longer duration, and broader spatial coverage. In all provinces, the cold vortex-type EHR accounts for the highest proportion. The proportions of the WPSH and typhoon types exhibit clear spatial gradients, with higher frequencies in the east and south than in the west and north, whereas the weak synoptic forcing type shows the opposite pattern. The WPSH and typhoon types occur most frequently in August, and at night. while other types occur most frequently in July and in the afternoon. The cold vortex, westerly trough, and weak synoptic forcing types occur in conditions with relatively lower moisture, but are characterized by stronger static instability and more pronounced mid-level dry air. In contrast, the typhoon and WPSH types occur in warmer, moister environments with higher near-surface relative humidity, stronger low-level jets, and vertical wind shear. Compared to short-duration heavy rainfall (20~50 mm·h^-1), all EHR types occur in environments with higher convective available potential energy (CAPE) and higher near-surface relative humidity. These results provide a preliminary characterization of the spatiotemporal distributions and environmental parameters of EHR in Northeast China under the influence of different synoptic systems, providing a basis for improving EHR forecasting in the region.