We conducted this study to clarify the impact of regional climatic conditions on the energy consumption in the commercial sector, in Japan. For this research, we utilized the Database for the Energy Consumption of Commercial Buildings (DECC), which provided data on the individual buildings. The existing energy consumption pattern derived from the individual building data seems to have large variations depending on climatic conditions. Therefore, in this research, connections were made between the seasonal fluctuations in energy consumption as well as the seasonal temperature changes, in order to extract the components of variation due to temperature, and make a regional comparison. In addition, we prepared estimating equations for the energy consumption based on temperature. By applying the regional temperature data to these equations, the impact of temperature alone was extracted for comparison. The results showed that, for the types of buildings addressed in this research, even though there is a regionality to the ratio of increments during summer and winter with regard to heating and cooling, it is offset by summing them up. In this research, we were able to roughly determine the level of fluctuations in the energy consumption as an impact of temperature. (C) 2017 Elsevier B.V. All rights reserved.