As problems of meeting energy demand and promoting sustainable development become more serious, saving energy and reducing consumption in the building industry has gained increasing attention. In building air-conditioning (AC) design, the AC equipment is usually selected depending on the design weather data. Therefore, appropriate design weather data to determine the kind of AC equipment and design for building energy conservation is necessary. Compared to the existing Technical Activities Committee (TAC) method for creating weather data for AC design, a method to create the design weather data using two weather indices for Osaka, Japan with consideration of the simultaneous occurrence and continuous occurrence of each weather element is shown in this paper. In addition, peak hourly thermal loads of a simulation building were evaluated through these created weather data and weather data created using the TAC method. It showed that the weather data created using the TAC method and the mean daily enthalpy as the first index may lead to an overestimation in heating design. The weather data created using the TAC method and the mean daily dry-bulb temperature as the first index may lead to an overestimation in cooling design. (C) 2016 Elsevier B.V. All rights reserved.