Studying the reaction of glaciers to climate warming and the interactions of ice masses with the atmosphere is cognitively highly significant and contributes to understanding the climate change. The results from the modelling of glacier surface ablation by the temperature–index and energy balance models as well as the results of meteorological and glaciological studies on Werenskioldbreen (south Spitsbergen, Svalbard) in 2011 have been analysed to improve the understanding of the glacier system’s functioning in the High Arctic. The energy balance modelling results showed that the radiation balance (58%) and sensible heat (42%) are the main factors influencing surface ablation on the glacier. The energy balance model offers a better fit to the measured ablation than the temperature–index model. These models have to be validated and calibrated with data from automatic weather stations, which provide the relevant gradient and calibration and validation. Presented models are highly suited for calculating ablation in Svalbard and other areas of the Arctic.