Intensity of heat stress in 2015 and 2018 summer seasons in the region of the Lower Silesia (Poland)

Abstract

The main goal of this paper was to assess the intensity of heat stress in Lower Silesia, Poland, during selected weather events characterized by high air temperatures. The complex impact of weather on the thermal load of the human organism is presented using the Universal Thermal Climate Index (UTCI). The analysis was carried out for the 2015 and 2018 summer seasons and compared with the multiannual period of 1971–2018. It was based on meteorological data from the IMGW-PIB stations of Wrocław, Jelenia Góra and Śnieżka. In order to examine how heat conditions affect UTCI in different geographical regions, stations located at different altitudes and representing the lowlands, the lower mountain zone and the summit zone of the Sudetes Mountains were considered. The research showed that during the most extreme thermal events, UTCI values in the lowlands and the lower mountain zones can be among the highest heat stress classes. In the summit zone, the maximum UTCI values are usually classed as ‘no thermal stress’.

Evaluation of Tourism-Climate Conditions in the Region of Kłodzko Land (Poland)

“…In the cold season, slight, moderate, and strong cold-stress categories were predominant. Similar conditions are typical for the regions located in the lowlands and the lower mountain zones of Poland and Central Europe [10,23,48,50,51,53,54,[66][67][68][69][89][90][91]. The analysis carried out in the paper showed that the frequency of moderate heat stress in July and August in the lower hypsometric zones of Kłodzko Land was about 5% lower than in the Carpathian region, confirming the results of the previous studies [48].…”

“…Such similarities were also noticed for cold-stress categories. However, it should be emphasized that the highest parts of the Sudetes Mountains are characterized by a very high number of days with extreme cold stress and no heat stress occurrence [52,[67][68][69]. In the discussed region, such conditions may be observed in the summit zone of theŚnieżnik Massif and the Bystrzyckie Mountains, which are the highest ridges in Kłodzko Land.…”

“…According to Ojrzyńska's classification, most of strong and very strong heat stress cases occurred under SW-A and NE-A circulation types, and were mainly related to the advection of tropical and continental polar air masses. The advections from these directions often contribute to heat-stress presence in Central Europe [49,50,[52][53][54]64,67,68]. Considering the percentage of days with UTCI > 32 • C under particular circulation conditions, the XX-A and SE-A types were characterized by a very high fraction of strong and very strong heat stress.…”

“…Simultaneously, the studies also indicated that the UTCI can be higher than 40 • C during the most intensive heat wave periods. Such conditions are also observed in the region of southwest Poland, including the lowlands [66] and the lower mountain zones of the Sudetes Mountains [48,[66][67][68]. The entire Sudetes region in the warm half-year is characterized by a relatively low number of days with thermoneutral conditions which are the most favourable for tourists and bathers [48].…”

“…The entire Sudetes region in the warm half-year is characterized by a relatively low number of days with thermoneutral conditions which are the most favourable for tourists and bathers [48]. On the other hand, in the higher parts of the Sudetes Mountains, the UTCI is more often related to cold stress, while heat stress is rarely observed, or does not occur at all [48,[67][68][69]. On the summits, cold stress prevails throughout the year, and the weather related to the most intensive cold stress can occur on more than 50% of winter days [69].…”