Research into heavy rainfall （hereafter referred to as “heavy rainfall”） that causes large‐scale sediment‐related disasters is progressing. Previous studies have argued that heavy rainfall is caused by the convergence of warm and humid currents due to isolated mountain ranges and narrow topography, and that this factor is general. This study builds on this previous research by focusing on the physical localization of heavy rainfall due to physical phenomena, and aims to clarify the regional characteristics associated with differences in the topography of the analyzed area and differences in the wind direction of warm and humid currents. The area analyzed was the Tateyama Caldera area upstream of the Joganji River in Toyama Prefecture, which has been hit by heavy rainfall four times in the past. Using the WRF, we applied warm and humid currents with ３６０° wind directions from multiple directions and conducted a experiment to analyze the change in precipitation distribution due to changes in the wind direction of the warm and humid currents （precipitation amount analysis by wind direction）. The results showed that heavy rainfall occurs when the wind direction is “west‐southwest” or “slightly northwest‐west”. We analyzed the relationship between these results and weather charts by the Toyama Meteorological Observatory and wind direction in a long‐term reanalysis dataset from past heavy rainfall events in the Tateyama Caldera region. As a result, the WRF experimental results were able to explain the four heavy rain events that occurred in the Tateyama Caldera area, and were able to explain them as regional characteristics of the Tateyama Caldera area.