Reflections of global warming in trends of temperature characteristics in the Czech Republic, 1961–2019

Abstract

AbstractThis paper presents a comprehensive trend analysis of spatiotemporal temperature change patterns over the territory of what is now the Czech Republic (CR) during the 1961–2019 period. Employing daily mean temperatures (TAVG), maximum (TMAX) and minimum (TMIN) temperatures and diurnal temperature range (DTR), supplied by 133 stations of the Czech Hydrometeorological Institute, daily, monthly, seasonal and annual series were calculated for four altitudinal groups and the entire CR, for which linear trends were calculated and further analysed. For the purposes of relative trend comparison, the linear trends were also calculated from standardized series (mean 0, SD 1, in 1961–1990). All seasonal and annual TAVG, TMAX and TMIN series exhibit statistically significant increasing trends, with the exceptions of only a few cases for winter (DJF) and autumn (SON). DTR trends increase significantly in spring (MAM) and summer (JJA), but decrease in DJF and SON. The highest increases in trends occur in JJA and from stations at lower altitudes for groups I (up to 300 m asl) and II (301–600 m asl). Trends in JJA and SON TMIN are relatively higher than in TMAX, while the opposite holds true of DJF and MAM. Comparing the three decades after 1990 with the 1961–1990 normal, each decade was generally warmer than the previous period, with particularly enhanced warming in 2011–2019. This is also reflected in prominent increases in cumulative temperature sums throughout the year. The results obtained are discussed in the context of other European papers and with respect to explaining existing differences.