As the climate heats, climate scientists predict that the effects will not be smoothly spread out over time nor space. It will be lumpy. Some times and some places will see particularly increased temperatures.
Apparently, Western Europe is predicted to especially get heatwaves: more than other comparable parts of the northern hemisphere. Temporarily sweltering in unusually high temperatures during the northern summer is going to be usual.
So, if you live in Western Europe then start seeing a yearly heatwave with abnormal highs not as an if and as strange but rather as a when.