Winter human thermal sensation based on micrometeorological measurements in Ioannina City, Greece

Human thermal sensation in urban environments significantly influences outdoor comfort and urban planning. In Mediterranean mountainous cities like Ioannina, Greece, cold winters necessitate a deeper understanding of microclimatic impacts on thermal comfort. This study assesses winter human thermal sensation using micrometeorological measurements along a specified urban route.

Air temperature, humidity, wind speed, and globe temperature measurements were conducted in January 2025 along a 6.67-kilometer route in Ioannina. The route was designed to capture diverse urban features, including open squares, narrow streets, and green spaces. Data were recorded at 2-second intervals at a height of 1.1 meters—corresponding to the gravitational center of the human body—for precise biometeorological analysis. Measurements were taken between 15:00 and 17:00 (UTC+3:00). The study estimated the human thermal indices Physiologically Equivalent Temperature (PET) and Universal Thermal Climate Index (UTCI), both based on human energy balance, to evaluate thermal sensation in Ioannina's green-urban environments.

The analysis revealed significant spatial variations in human thermal indices along the route, demonstrating the impact of urban microclimate on winter thermal sensation in Ioannina. Open areas with higher solar exposure exhibited higher index values, while shaded, wind-exposed streets recorded lower values. These findings highlight the importance of urban design strategies that enhance winter thermal comfort by maximizing sun exposure and providing wind protection. Additionally, local adaptation to winter conditions should be considered when planning outdoor urban spaces, as individuals generally express high satisfaction with the thermal conditions in winter. In contrast, the combination of high air temperatures, intense solar radiation, and low wind speeds leads to thermal discomfort in the summer.

Future research should incorporate subjective thermal sensation surveys to complement the objective micrometeorological data, providing a more comprehensive understanding of human thermal comfort in urban settings.