Assessment of thermal indices applicability in Cyprus

Thermal indices are commonly used to assess outdoor thermal environments. This study aims to examine the applicability of popular thermal indices for the assessment of thermal sensation in Cyprus. Field surveys were conducted in outdoor public sites in five districts of the Republic of Cyprus. The surveys involved environmental monitoring and questionnaire-based interviews of pedestrians. The pedestrians reported their thermal sensation using a nine-point scale, the actual thermal sensation (ATS). Thermal sensation predicted by Discomfort Index, Heat Index, Humidex (HU), Physiologically Equivalent Temperature (PET), Predicted Mean Vote (PMV), Standard Effective Temperature, Universal Thermal Climate Index, and Wet-Bulb Globe Temperature (WBGT), was compared to ATS. Spearman’s rho, Goodman and Kruskal's gamma, percentage of correct predictions, and distribution of indices’ predictions per category of ATS were used to assess indices’ applicability and find the index that best predicts thermal sensation. The analysis was performed for participants living in Cyprus (locals) and for visitors (non-locals). The indices predicted successfully a low percentage of ATS ranging in locals between 9.6% (HU) and 20.7% (PMV), and in non-locals between 13.9% (WBGT) and 29.9% (DI). Overall, PET performed better predicting successfully 16.8% of ATS in locals and 27.3% in non-locals.