Thermal Comfort of Waterfront Walkways in Urban Parks: Objective Environmental Conditions and Subjective Perceptions

Vegetation and water are widely used to mitigate heat in urban parks, but how their combined configurations influence thermal comfort along waterfront walkways remains insufficiently understood. Moreover, whether physiological equivalent temperature (PET) reflects visitors’ actual thermal experience remains unclear. This study examined eight purposively selected waterfront walkway scenes representing the main walkway types along the lakeside routes of Xuanwu Lake Park, Nanjing, China. ENVI-met was used to simulate air temperature, relative humidity, wind speed, mean radiant temperature, and PET under clear hot-weather conditions. Field measurements—wind speed at one scene and air temperature and relative humidity at two further scenes—were used to evaluate the simulations, and 295 questionnaires assessed thermal sensation votes (TSVs), thermal comfort votes (TCVs), behavior, and environmental perceptions. The simulations indicated clear differences among scenes associated with canopy shade, water-edge openness, paving, and airflow. At the scene level, PET and TSV showed similar patterns at the coolest and warmest scenes, while several intermediate scenes diverged, suggesting that thermal experience was also shaped by local shade, airflow, humidity perception, and water-related experience. After accounting for the clustering of respondents within eight waterfront scenes, the final mixed-effects model yielded a marginal R2 of 0.418 and a conditional R2 of 0.439. Longer stays and an obvious perceived water-cooling effect were associated with higher TCV, while respondents who preferred drier conditions reported lower TCV than those who preferred more humid conditions. These associations were also supported by the ordinal sensitivity analysis, although the relationship involving longer stays may partly reflect self-selection. These findings show that waterfront thermal comfort reflects the combined effects of vegetation–water configuration and user experience, and provide evidence for the climate-responsive design of comparable hot–humid lake parks.