RWTH Geographers Record All-Time High Temperature in Aachen

On July 25, 2019, an all-time high temperature of 40.0 degrees Celsius was recorded in Aachen. This is the highest measurement since records began in 1901 and the first time the temperature reached 40.0 degrees Celsius in the city. The previous records of 37.0 degrees Celsius, registered in 1911, and 37.7 degrees Celsius in 2015, were broken on July 24, 2019, when the temperature hit 38.1 degrees Celsius.

The measurements were recorded two meters above ground, at RWTH Department of Geography's Aachen-Hörn Weather Station, where data have been registered since 1980. For comparison purposes, measurements from the weather station operated by the German Weather Service – DWD at Wingertsberg, in Aachen's Stadtpark, from 1901 to 2011, were also taken into account.

This is already the eighth "hot day" this year. This means the maximum temperature soared to more than 30 degrees Celsius, which normally occurs just three to four days each year. Further, this is also the third day this year that a temperature over 35 degrees Celsius was recorded. In the 30 years from 1961 to 1990, currently called the "normal period", the maximum temperature only exceeded 35 degrees Celsius on four days. By contrast, we have already had 29 of these days since 1991.

According to the RWTH researchers, the current weather conditions have been caused by subtropical air masses from the Mediterranean, which have been carried unusually far, all the way to Central Europe. Very high summer temperatures often occur in comparable weather conditions, which have been on the rise since the 1990s and indicate a clear sign of climate change. Moreover, the thermal effect of the ever-increasing number of building developments in recent years has also exacerbated the effects of heat waves in cities.

Source: Press and Communications