Dynamic evaluation of outdoor thermal comfort in an urban park situated in a tropical region

This study employed a longitudinal design along a 1,390-meter walking route in an urban park in a hot, humid climate. Environmental variables were continuously monitored using a backpack-mounted device equipped with low-cost microclimatic sensors. Subjective thermal environment assessments were conducted at six designated points along the route, with questionnaires administered to 103 participants across wet and dry periods. Comparison of subjective assessments with the Universal Thermal Climate Index (UTCI) revealed discrepancies in perceived thermal sensation. Rather than an inherent metric inaccuracy, these findings highlight the index's predictive limits and scale-resolution challenges under dynamic field conditions. While subjective assessments showed statistically significant correlations with air temperature, relative humidity, and the UTCI, the practical magnitude of these relationships was weak due to the repeated-measures design. This indicates that direct microclimatic variables alone explain limited variance in transient human comfort. Point-by-point comparative analysis revealed that spatial factors profoundly dictate thermal perception. Notably, densely shaded locations produced a sultry canopy effect during overcast, wet conditions, in which restricted airflow and trapped humidity elevated thermal stress despite lower ambient air temperatures. Ultimately, the study underscores the importance of capturing sequential thermal experiences, environmental contrast, and cumulative metabolic demands, particularly during the final uphill spatial transition. This research advances the evaluation of outdoor thermal comfort in the Global South through affordable dynamic monitoring and clarifies the complex microclimatic role of urban parks.