Verification of precipitation is one of the major issues in evaluating numerical weather prediction. In this study, a recently developed neighbourhood‐based method in terms of agreement scales is applied to characterize the scale‐dependent spatial spread‐skill relationship of precipitation forecasts in a 3 km convection‐allowing ensemble prediction system (EPS) over the Yangtze‐Huaihe river basin of China. Thirty cases during the Meiyu season of 2013 are classified into two weather regimes, large coverage (LC) and small coverage (SC), based on the precipitation fractional coverage. Overall, precipitation distributions for these two weather regimes are reasonably forecast by the EPS. The results show that the spatial spread‐skill relationship depends highly on the weather regime. The spatial spread‐skill relationship under SC is poorer and shows more diurnal variation compared to that under LC. In addition, this article extends the neighbourhood‐based method to investigate the relative influence of precipitation intensity and placement on the spatial spread‐skill relationship. With increasing precipitation threshold, the relative impact of precipitation intensity on the relationship gradually decreases, and the influence of precipitation placement becomes dominant. Domain of the convective‐scale EPS with coastlines, province boundaries and topography heights, and the verification domain of precipitation forecasts (inside thick solid lines).