Heat waves in Central Europe (1991-2006)

The extreme weather phenomenon of heat waves poses a serious threat to humans and has been shown to contribute to increased sickness rates and even deaths, mostly in large cities. The paper concerns the occurrence of heat waves in Central Europe. Data was collected from five regional weather stations in Budapest, Krakow, Lvov, Prague and Vienna and included records of the average, maximum and minimum daily air temperatures during the period 1991-2006. The authors defined a heat wave as an unbroken period of at least three days with a maximum temperature of more than 30 degrees C. The study demonstrates that the greatest intensity of heat stress is observed during short heat waves that lasted typically for three to four days and whose timing did not coincide at the different stations involved. Indeed, even longer heat waves, characterised by lower temperature values, were not always recorded at all the stations. This was due to the division of the region by mountain ranges, which impeded the flow of hot tropical air into southern Poland and western Ukraine.