The goal of this study is to test applicability of the conceptual catchment run-off HBV model to simulate discharge in small non-glaciated Arctic catchment. Within two ablation seasons, 2014 and 2015, in the Fuglebekken catchment (Spitsbergen, Svalbard), selected hydro-meteorological measurements were conducted, including discharge measurements in 10 min interval by Nivus PCM-F device with active Doppler sensor. The model parameters were calibrated on discharge measurements from both years separately and verified independently. As the transformation from rainfall to runoff includes a number of processes with different dynamics and timescales, the proper description of the processes and their simulation of discharge depend on the temporal resolution of the data. For that purpose, the relationships between the calibration and validation results, and optimal model parameters with different time steps were analyzed. It was found that calculated fit of simulated to observed discharge, depends on the year, time step and data averaging. The best results were obtained for the model from year 2015 for 3 and 6 h using averaged input data.