Analysis by scientists from the World Weather Attribution group found temperatures in the UK, Germany, France, Italy and Spain were between 5C and 12C above the seasonal average.
In a study, the research group also found that in 45% of 854 European cities examined, heat records had been broken or were forecast to be broken. The researchers measured what is known as the wet bulb globe temperature, a metric that combines air temperature, humidity, wind speed, and solar radiation to estimate how much heat stress people are likely to experience in real-world outdoor conditions.