Abstract:The climate comfort index is the basis of the forecast of weather comfort degree and climate suitability assessment for tourism. Various bioclimatic indices have been developed with their own purposes. However, they could not be able to accurately describe human comfort perception to different weather conditions in various climate zones in China. To fill this gap, a new universal and semi-empirical climate comfort indicator (outdoor weather comfort index, OWCI) is proposed based on the previous results on the relationships between meteorological elements and human thermal comfort and the analysis of meteorological element characteristics in different regions of China and questionnaires. The OWCI model consists of five components that describe the impacts of daily average and maximum temperatures, humidity, wind speed and radiation on human comfort perception, respectively. The impact of the temperature on the effects of humidity, wind and sunshine is taken into account. The OWCI allows for more weather elements and interactions between them than the empirical models in use so far, so it could depict its capability of capturing human comfort perception in the daytime. Verification questionnaires and case studies in different climatic regions in China show that the OWCI could reflect the subjective comfort perception of respondents much more accurately under various weather conditions. Therefore, it could be more widely applied in different seasons and climate zones across China wherever the basic meteorological data are available. Furthermore, the data of OWCI are suitable for statistical analysis, which is conducive to spatiotemporal evaluation and assessment of climate change impacts on comfort perception.