Sediment‐related disasters caused by fronts and typhoons have led great damage. However, the causes of sediment‐related disasters have remained unknown on the spatial and temporal scales of their occurrence. Makino et al. (2024a) analyzed the heavy rain that occurred in the upper reaches of the Tenryu River in1961and discovered the following; the factor of the heavy rain is that the surrounding meteorological field causes rainfall, and warm and humid air currents from the Pacific Ocean converge on topography such as independent peaks and narrow terrain. Therefore, we used WRF (Weather Research & Forecasting Model) to examine the influence of topography on convergence for two heavy rains: Aso in July 2012 and Shikoku in July 2018. In addition, without using WRF, we analyzed the 25 heavy rains that caused 10 or more deaths since 1961 (Aso in July 2012 is included in 25 heavy rains), based on the relationship between the meteorological field and the topography. As a result, we found that independent peaks and constricted landforms that exist upwind of the disaster area cause convergence in these lee sides, and that convergence intensifies rainfall. It was also found that windward convergence due to mountain ranges downwind of the disaster area intensifies heavy rain when convergence occurs due to independent peaks or narrow terrain. This conclusion was derived from WRF experiments in two sediment‐related disasters that caused major damage, and the actual situation of 25 sediment‐related disasters that caused major damage. It suggests that heavy rain has regional characteristics and that these factors of occurrence can be generalized because they are physical phenomena.