Time series of average summer (black) and maximum summer (red) daily maximum temperatures averaged over England and Wales, 1960-2021. Trend-lines are also shown for each time series. Credit: Matthew Patterson, Department of Physics, University of Oxford.
Key points:
- Climate change is causing extremely hot days in Europe to warm twice as fast as “normal” summer days.
- The study analyzed data from the past 60 years, recording the maximum daily temperature.
- Expediated climate change in Spain could be impacted the hottest days seen in Northwest Europe.
New research has found that climate change is causing the hottest days in Northwest Europe to warm at double the rate of average summer days—and current climate models are underestimating that rate compared with observations. The difference is most pronounced for England, Wales and Northern France, according to the research team from the University of Oxford.
For the study, published in Geographical Research Letters, researchers analyzed data from 1960 to 2021, recording the maximum daily temperature, provided by the European Centre for Medium-Range Weather Forecasts. Although the maximum recorded temperature varied between years, the overall trend clearly showed that the hottest days for North-West Europe had warmed at twice the rate of average summer days.
For example, in England and Wales, the average summer day increased by approximately 0.26°C per decade, while the hottest day increased by around 0.58°C per decade. However, this faster warming of the hottest days was not observed to this extent elsewhere in the Northern Hemisphere.
The reason behind the faster warming conditions is still unknown, but researchers say there could be a link between Northwest Europe’s hot summer days and hot air being transported north from over Spain—an area warming at a faster rate. The hottest days of 2022, for instance, were driven by a plume of hot air carried north from Spain and the Sahara. However, further research is needed to verify this.
“Understanding the warming rate of the hottest days will be important if we are to improve climate model simulation of extreme events and make accurate predictions about the future intensity of such events. If our models underestimate the rise in extreme temperatures over the coming decades, we will underestimate the impacts this will have,” said lead author Matthew Patterson.