Changing thermal bioclimate in some Hungarian cities

Today we can say that the climate change is a scientific fact. The majority of climate change research analyzes only the future conditions. However, we need to know that the future changes cannot be determined without knowledge of the past changes. In this paper the detected changes of thermal bioclimate are analyzed. For this analysis two different bioclimate indices were used. The first one is the Physiologically Equivalent Temperature, the well known bioclimate index, calculated by the RayMan model. The second one is a newly developed bioclimate index, the Universal Thermal Climate Index. Both indices have been calculated for Budapest, Debrecen, Szeged and Siofok, for 12 and 18 UTC. According to the results the annual means increased at both examined times of day. The seasonal means in spring and in summer increased unambiguously. In autumn and in winter the change is different. In winter the 1971-2000 averages are higher than the 1981-2010 averages. In autumn, the 1971-2000-s averages are generally lower than the previous 30-year average. But the last averages exceed all the 1971-2000 averages