The main objective of the present quasi-experi- mental study was to examine the influence of culture (Swedish vs Japanese) and environmental attitude (urban vs open-air person) on participants’ thermal, emotional and perceptual assessments of a square, within the PET (physiological equivalent temperature) comfortable inter- val of 18–23°C. It was predicted that persons living in different cultures with different environmental attitudes would psychologically evaluate a square differently despite similar thermal conditions. Consistent with this prediction, Japanese participants estimated the current weather as warmer than did Swedish participants and, consistent with this, they felt less thermally comfortable on the site, although participants in both countries perceived similar comfortable thermal outdoor conditions according to the PET index. Compared to the Japanese, the Swedes estimated both the current weather and the site as windier and colder, indicating a consistency in weather assessment on calm-windy and warm-cold scales in participants in both cultures. Furthermore, Swedish participants felt more glad and calm on the site and, in line with their character (more glad than gloomy), they estimated the square as more beautiful and pleasant than did Japanese participants. All this indicates that thermal, emotional and perceptual assessments of a physical place may be intertwined with psychological schema-based and socio-cultural processes, rather than fixed by general thermal indices developed in line with physiological heat balance models. In conse- quence, this implies that thermal comfort indices may not be applicable in different cultural/climate zones without modifications, and that they may not be appropriate if we do not take into account the psychological processes involved in environmental assessment.