Western Europe has experienced a heat wave in recent days, resulting in hundreds of broken June and historical temperature records across the region. France recorded its hottest day on Tuesday.

The UK Met Office issued extreme heat alerts for central and southern England and Wales. Temperatures in some areas of southern England exceeded 30 degrees Celsius (86 degrees Fahrenheit) in the last three days. Forecasters estimate temperatures in southern England will reach 35 degrees Celsius on Wednesday and Thursday, with some locations possibly exceeding 38 degrees Celsius (100 degrees Fahrenheit).

Heat records are also being broken from Spain to Germany. Temperatures in western and central France are expected to exceed normal levels by 15 degrees Celsius (27 degrees Fahrenheit), reaching 40 degrees Celsius (104 degrees Fahrenheit) in some areas, including Paris. France also recorded its second hottest night in history on Tuesday, with a national average temperature of 21.5 degrees Celsius (70.7 degrees Fahrenheit). Temperatures in Paris did not drop below 25.5 degrees Celsius (77.9 degrees Fahrenheit) during the night on Tuesday. On Wednesday morning, local temperatures exceeded 30 degrees Celsius (80 degrees Fahrenheit) on the island of Corsica at 8:00 a.m.

58 of 96 continental regions in France were under the most severe red heat alert on Wednesday. Approximately 68,000 households in the Finisterre region of Brittany lost power on Wednesday morning. Local authorities stated that priority is being given to "sensitive" facilities such as hospitals and nursing homes for power repairs in Finisterre.

Two people, including a six-year-old child, drowned in France on Tuesday night while attempting to cool off. At least 42 drowning victims have been recorded in France since June 18.

Peter Thorne, director of the ICARUS Climate Research centre, stated, "Basically, we are cooking in our homes in many cases in much of Europe." He noted that "Houses have generally been designed to retain heat." He advised, "If you have shutters, close the shutters... Towels or things you can put against the window to cool the windows... Do not open the window in the middle of the day. That is the worst thing you can do." He added, "So look for cool areas as much as you can, use the amenities and supports that are available." Thorne stated that the climate crisis is aggravating what would have been an "anomalously warm" summer and that heat waves like the one affecting Europe are "enhanced by humans, by our greenhouse gas emissions that trap heat." He also stated that climate change is likely adding three or four degrees to temperatures.

The extreme weather conditions are caused by a heat dome, a high-pressure weather system that can trap heat for days or weeks. Human burning of fossil fuels has intensified the heat through climate change.

Heather Massey, a doctor at the Extreme Environments Laboratory at the University of Portsmouth, noted that "Higher levels of humidity in the air reduce the effectiveness of perspiration, which is what would cool the body." Hugh Montgomery, a professor of intensive care medicine at University College London, explained, "If you are in a very humid environment, say with 100% humidity or close to that level, it is impossible for water to evaporate." He added, "Therefore, there can be no cooling effect, and sweat will simply drip, and dripping sweat has no cooling benefit." Montgomery stated that temperatures of 36 degrees Celsius (97 degrees Fahrenheit) become dangerous with 65% humidity. He also stated that at 42 degrees Celsius (107.6 degrees Fahrenheit), 35% humidity can be "quite lethal."