A bootstrap-based differential split-sample test to assess the transferability of conceptual rainfall-runoff models under past and future climate variability

•An enhanced split-sample test to assess transferability of hydrological models.•Clear limits of model transferability towards drier and hotter climate conditions.•Some climate projections fall outside the transferability limits of the models.•Some calibration periods lead to underestimate impact of climate change on runoff.•We suggest selecting a past sub-period as close as possible to the future climate.