Thermal comfort in belgrade, serbia: utci-based seasonal and annual analysis for the period 1991-2020

The main goal of this research is to examine thermal comfort in the central area of Belgrade (Serbia), over a period of 30 years (1991-2020). The Universal Thermal Climate Index (UTCI) was used as a measure for evaluating outdoor thermal comfort (OTC). The obtained results were considered separately for each season, as well as at the annual level. The analysis was carried out on the basis of an extensive database, which included hourly values (7h, 14h, 21h CET) of meteorological parameters, as well as their average daily, minimum, and maximum values. The obtained values of UTCIs show a positive growth trend during all four seasons. A significant increase in the annual values of UTCIs was also recorded. Four of five years with the highest average UTCIs were recorded in the last decade of the survey, more precisely in the period 2015-2020. The years that stand out for the frequency of record spring, autumn and winter UTCIs values are 2017, 2018, 2019 and 2020. On an annual level, minimum UTCI value has rising trend of 0.099 degrees C/year, while at maximum UTCI value, that trend is 0.081 degrees C/year.