Applicability of open rainfall data to event-scale urban rainfall-runoff modelling

•Open gauge and radar rainfall data as input to rainfall-runoff model are studied.•Runoff simulations are conducted at a 33.5ha urban catchment in Helsinki, Finland.•Distance to catchment largely dictates suitability of gauge data as input source.•Open radar data may outperform gauge data 2.5–5km from catchment.•Gauge correction and advection interpolation improved the radar product performance.