The 2021 European Heat Wave in the Context of Past Major Heat Waves

Abstract

AbstractThe past two decades in Europe have been characterized by numerous major heat waves, with record‐breaking temperatures reported also during the summer of 2021. While most previous studies on heat waves were based on land‐only datasets (station or gridded), we use the ERA5 reanalysis to capture also heat wave characteristics over water bodies. An up‐to‐date list of major European heat waves since 1950 is presented, and the 2021 heat wave is evaluated in this long‐term context. This event was record‐breaking in length at the European scale, and in many other aspects (spatial extent, magnitude) comparable to the 2003 and 2010 major heat waves. The summer of 2021 was unprecedented over Europe according to the number of hot days (63) and the earliest start of a major heat wave (June 19), while the 2019 heat wave with record‐breaking temperatures across Western Europe stands out as to its intensity. Another recent major heat wave in 2018 ranked fourth in terms of magnitude. The spatial pattern in occurrence of the most severe heat wave since 1950 in individual parts of Europe is dominated by the 2003 (Western Europe), 2010 (Eastern Europe), 2018 (Scandinavia), and 2021 (Mediterranean) major heat waves. Overall, 83% of the domain area experienced the most severe heat wave in the past two decades (2002–2021), which demonstrates a rapidly changing summer climate in Europe.