The problem of heat island is becoming more and more urgent as the climatic situation worsens. Moreover, the problem has already reached the level of normative documents. The authors consider the problem on the example of one of the largest cities—Yekaterinburg. At first, the authors critically analyze existing methods and data sets to identify the heat island. As a result of the critical analysis, the authors come to the conclusion that both the concept of heat island and methods of its localization are currently not sufficient to meet the regulatory requirements. According to the authors, it is necessary to solve the problem of designing a system of observation posts for monitoring the heat island.