The authors present the results of mapping the “heat island” surface in the city of Tyumen and determining its spatial and seasonal manifestations using the Landsat-8 satellite data. Geothermic scenes of four seasons were obtained and analyzed: winter – 20.01.2015, spring – 03.04.2015, summer – 22.06.2015, autumn – 20.11.2015. To perform an assessment of the “heat island” effects the year of 2015 was selected, in which the “heat waves” were recorded. The study established the presence of a “heat island” and its temperature anomalies. Its temperature values are obtained from the difference between the data in the area of the weather station (“countryside”) and the average temperatures within the boundaries in Tyumen (“city”). The values of anomalies is the difference between the maximum (or minimum) and the average temperatures there. This data in “countryside” and “city” make the background for urban and suburban areas. The “heat island” effect is most pronounced in winter (the excess of the “city” average temperature values over the background ones in the meteorological station area (“village”) is 4 °С), but is also present in other seasons (in spring – this excess is 2,6 °С, in summer and autumn periods – 0,6–0,8 °С). Significant anomalies in winter were noted over industrial and energy objects (the temperature difference was 17 °С), in autumn – over energy facilities (discrepancy 14,3 °С), in spring and summer – over industrial structures (8 –13 °С incongruity). Those phenomena were recorded: in summer – mainly over water bodies and green areas, in winter – over non-built-up and non-vegetated areas. As a result of the “heat island” effect spatial and seasonal manifestation analysis, the urban areas with stable temperature anomalies were identified.