Summer UTCI variability in Poland in the twenty-first century

Abstract

The paper analyses the temporal and spatial variability of the Universal Thermal Climate Index (UTCI) in Poland in summer. Summer is the season with the highest intensity of tourism traffic that is why it is important to determine biometeorological conditions, especially in popular tourist destinations such as coastal, mountain and urban areas, in the times of climate changes. The analysis was based on data from 18 stations of IMGW-PIB (Institute of Meteorology and Water Management-National Research Institute), distributed evenly in the territory of the country, and representing all eight bioclimatic regions. The data include air temperature, relative humidity, wind velocity and cloudiness at 12 UTC from summer months: June, July and August from the years 2001-2018. Thermoneutral zone was the most frequently occurring UTCI class in Poland. It was recorded during 56-75% of summer days (with the exception of mountain stations, where it occurred on 30-35% of days). Moderate heat stress is the second most frequently occurring category with a frequency from 18 to 29% with the exception of mountain and coastal areas. Extreme and very strong cold stress occurred particularly in high mountain stations, and was sporadically observed at the coast of the Baltic Sea; however, the occurrence of such conditions decreases, which if favourable for beach tourism. No cases of extreme heat stress were recorded in any of the stations. The most unfavourable bioclimatic conditions were characteristic of the Upland Region (IV), represented by Kraków and Sandomierz, where very strong heat stress occurred with a 10% frequency. This is a limitation for urban tourism in those regions. The highest UTCI values were recorded in Kraków on 17 July 2007 and 29 July 2005. The highest number of cases with strong and very strong heat stress was recorded in 2015 as a consequence of the heat wave observed in Poland in the first half of August. In the majority of the analysed stations, in the second half of the analysed period (2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018), an increase in the number of days with strong and very strong heat stress was observed in comparison with the first half of period (2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009). The highest frequency of such days was observed in July. Based on the data, there are 4 potential periods of occurrence of such days, with two most intense being 26. July-13 August and 14-22 July.

The evaluation of biothermal conditions for various forms of climatic therapy based on UTCI adjusted for activity

“…However it should be noted that in winter UTCI values on the Polish coast decrease from west to east, and thus the degree of strain from cold stress in resorts in the western part of the coast is lower than in the Hel peninsula area (Koźmiński & Michalska, 2019). Strong heat stress most often (4% of days) appeared and lasted the longest (from the end of April to mid-September) in the south-east part of the country, in Busko-Zdrój, which confirms that the Upland Region is the warmest bioclimatic region of Poland (Krzyżewska et al, 2020). Very strong heat stress was only sporadically observed in the studied resorts, and in the highland resort of Krynica-Zdrój it was not recorded even once.…”

“…It was also confirmed that coastal resorts (represented in this study by Kołobrzeg) are the most privileged in thermal terms, as in the warm half of the year they have the most days in Poland with thermoneutral conditions (Kuchcik et al, 2013). Furthermore, in summer the Baltic coast is the coolest and most windy region of Poland (apart from highmountain areas) (Krzyżewska et al, 2020), which is reflected in the lowest frequency of strong heat stress in this region. In winter, meanwhile, cold stress occurred in Kołobrzeg far less often than in Busko-Zdrój and Krynica-Zdrój, while very strong cold stress was not observed there at all.…”

Tourism climate conditions in the Western Sudetes (Poland) in relation to UTCI

“…It should be emphasized that such a tendency is also projected for the future period, including discussed area (Schwarzak et al, 2014;Miszuk et al, 2016) and other European regions (Matzarakis et al, 2007;Oehler & Matzarakis, 2007). On the other hand, no statistically significant trends for heat stress were observed for the discussed area, whereas such tendencies occurred in some other Polish regions for previous periods (Półrolniczak et al, 2016;Krzyżewska et al, 2020;Tomczyk & Owczarek, 2020).…”

The influence of air temperature diversity in Central Europe on the occurrence of very strong and extreme cold stress in Poland in winter months

“…The spatiotemporal patterns of thermal exposure in a moderate-climate urban area were per-formed for a domain in Prague. The UTCI across Poland has been analyzed (Błażejczyk & Kunert, 2011;Błażejczyk et al, 2015b;Kuchcik 2017Kuchcik , 2020Owczarek, 2019;Tomczyk & Owczarek, 2020;Krzyżewska et al, 2020;Wereski et al, 2020;Kuchcik et al, 2021). The index has been also used to assess bioclimatic conditions in different regions in Poland (e.g., Nowosad et al, 2013;Milewski, 2013;Kolendowicz et al, 2018;Błażejczyk et al 2020;Głogowski et al, 2020) and in Polish cities (e.g., Błażejczyk et al, 2016;Bryś & Ojrzyńska, 2016;Bartoszek et al, 2017;Okoniewska, 2020;Kuchcik et al, 2021).…”