Physiology and behavior of organism are directly related to temperature and have been recognized to be affected by the recent global warming. However, due to the complex nature of topography and various land cover, warming is highly spatially heterogeneous. Consequently, warming effects vary for a given species across space. In temperate regions, growth and metabolic rates of ectothermic vertebrate species, including fishes, are likely to be impacted by the warming as growth rates are predicted to increase with rising temperatures but then decline as individuals struggle to maintain cardiac function and respiration in the face of increased metabolic demands. Understanding the temporal and spatial patterns of the physiological processes, such as fish consumption, is important to predict future species distribution trends needed to develop effective management plans on a regional scale. In this study, we examined seasonal and spatial variations of Arctic Grayling (Thymallus arcticus) productivity and characterise how climate change affects growth and consumption rates in its geographical distribution. The results showed the amount of food consumed to gain a particular weight varies with season and differs in the distribution range. In the southern part, the coldwater species is more vulnerable in terms of metabolism since its optimum thermal habitat decreases, whereas in the northern part, climate change expands the suitable habitat for Arctic Grayling. Our data demonstrates that increasing water temperatures will push Arctic Grayling above the point where warming is beneficial for growth and suggests a overall range contraction as a result of warming.