Seasonal variation in outdoor thermal comfort and its influence on pedestrian behavior in a severely cold city in Northeast China

Abstract Understanding seasonal variations in outdoor thermal comfort and their behavioral implications is essential for climate-responsive urban design, particularly in severely cold regions, where extreme weather conditions strongly influence pedestrian experience. This study examines thermal perception and crowd behavior on urban pedestrian streets across different seasons in Harbin, a representative city in the severe cold region of Northeast China. Field measurements were conducted during the cold, hot, and transitional seasons, integrating meteorological observations (air temperature, humidity, globe temperature, wind speed, and solar radiation), Universal Thermal Climate Index (UTCI) calculations, subjective questionnaire surveys ( n = 1225), and behavioral mapping based on video analysis. The results revealed clear seasonal differences in thermal perception. The neutral UTCI temperature was lower in the transitional seasons (23.5 °C) than in the hot season (25.1 °C). These seasonal differences were consistent with the theoretical framework of alliesthesia, under which identical UTCI values produced different perceptual responses depending on the seasonal context. During the transitional seasons, thermal perception was jointly affected by multiple meteorological variables, whereas in the extreme seasons, air temperature was the dominant factor. In addition, pedestrian expectations of thermal comfort shifted beyond specific temperature thresholds, suggesting adaptive behavioral responses to seasonal conditions. Pedestrian volume, activity duration, and overall flow rate generally peaked near the thermal neutral boundary and gradually declined as UTCI shifted toward warmer conditions. Although this study provides new evidence on how thermal comfort is associated with pedestrian behavior across seasons in cold-climate cities, the analyses reflect statistical associations rather than causal relationships. These findings contribute to climate-responsive urban design strategies and provide scientific evidence for improving outdoor thermal environments in winter cities and optimizing seasonal street management.