The paper deals with juxtaposing the results of the in-situ (ground-based) temperature measurements and those of temperature calculations based on TIRS thermal satellite images (Landsat 8 satellite) for Kunashir island (Great Kuril ridge). Ground measurements were recorded using iButton temperature sensors installed at a height of 1,5–2 m from the earth’s surface (including under the forest canopy), thus they fixed the air temperature. From satellite images of 100 m spatial resolution, the values of the land surface temperature (LST) were calculated through the method developed by NASA. A strict dependence of the accuracy of determining these indicators according to Landsat 8 data on the landscape features of the area was not revealed. However, the minimal values of the difference are characteristic of the areas with dense woody vegetation, and the maximal ones are confined to settlements, the vicinity of solfataric fields and economic facilities of environmental protection. As a result of the regression analysis, a good connection was established between satellite and ground measurements. The standard error was 0,95. The determination coefficient is 0,99, and it confirms the high accuracy of temperature determination using satellite images.