Outdoor design conditions are weather data for design purposes showing the characteristic features of the climate at a particular location. In this study, new outdoor design conditions for cooling were determined for 78 locations within Turkey according to the format recommended by the American Society of Heating, Refrigerating and Air-Conditioning Engineers Inc. (ASHRAE). Dry-bulb temperature corresponding to 0.4, 1 and 2% annual cumulative frequency of occurrence and the mean coincident wet-bulb temperature, the mean and standard deviation of the annual maximum dry-bulb temperatures, and the mean daily ranges were obtained. In these calculations, the hourly data measured during at least 13 years were used. The current cooling design conditions used in the calculation of cooling load in Turkey were analysed based on their frequency levels. Comparison of the existing cooling design data with the data obtained in this study revealed that the current cooling design temperatures are generally stringent. (C) 2002 Elsevier Science Ltd. All rights reserved.