Just four days into July 2026, the United Kingdom and much of Western Europe have already experienced two historic, record-shattering heatwaves that experts say offer a clear preview of the region’s new, warmer climate reality. The extraordinary heat events came in rapid succession: an unseasonably warm May was immediately followed by a June heat event so intense that the United Nations’ weather agency labeled it extraordinary across the European continent. After only a short period of cooler temperatures, forecasters are already warning that a third heatwave is looming on the horizon.
While this string of extreme heat may feel out of the ordinary to most residents, climate scientists confirm it aligns exactly with long-held predictions for a human-warmed world. The primary driver of this shift is the continued burning of fossil fuels, which releases heat-trapping greenhouse gases into the atmosphere that raise global average temperatures. “Human-induced climate change has made events like this more likely and more intense,” explained Professor Stephen Belcher, chief scientist at the UK Met Office.
The scale of June’s temperature anomalies is unprecedented across the UK. Provisional data shows temperatures peaked at 37.7°C in Lingwood, Norfolk—far exceeding the UK’s previous all-time June record of 35.6°C, a mark that stood from 1957 until it was tied in 1976. Multiple weather stations across the country broke this decades-old record, and even the UK’s longest-running measurement sites saw their previous June records shattered by 2°C or more. “We normally expect the records broken by small amounts – tenths, maybe up to a degree or so,” noted Ed Hawkins, a professor of climate science at the University of Reading. “So to have it shattered by such a large amount is noticeable and extraordinary, and of course this comes after a similar event in May.”
June’s heatwave was made particularly oppressive by a dangerous combination of extreme high temperatures and elevated humidity. High humidity prevents the human body from cooling itself effectively through perspiration, leaving outdoor workers—who are among the most vulnerable groups to extreme heat—at heightened risk of heat-related illness. Overnight temperatures also remained unusually high across most of the UK, creating widespread “tropical nights” where temperatures never dropped below 20°C, a phenomenon that was extremely rare in the UK historically. On the night of June 24 into June 25, Cardiff recorded an overnight low of 23.5°C, making it the warmest June night ever recorded in the country. Hawkins explained that as global temperatures continue to rise, these uncomfortable, unhealthy tropical nights will become increasingly common across the UK.
The same high-pressure “heat dome” that triggered the record heat in the UK also smashed temperature records across the entire European continent. More than a dozen countries spanning western, central, and eastern Europe broke their national June temperature records, with some new records exceeding previous marks by 2 to 3°C. Multiple nations recorded temperatures above 40°C in June—a month that is typically far cooler than July—with some even setting all-time national temperature records for any month of the year. National weather agencies across the continent described the event as historic and exceptional: Germany’s Deutscher Wetterdienst called it “a heatwave for the history books,” while France’s Météo-France labeled it “exceptional” and “historic.” France and Spain also set new records for the hottest average national June temperature on record.
Even Switzerland, an Alpine nation with historically cool summer temperatures, recorded a June high of 39°C, beating its previous June record by more than 2°C. Sonia Seneviratne, a professor at the Institute for Atmospheric and Climate Science at ETH Zurich, noted that while the event was highly unusual compared to historical measurements, it did not come as a surprise to climate scientists who have long warned of rising heat extremes in a warming world. “When you know that we have a warming climate, I was not that surprised to see this happen,” she said.
Europe has emerged as one of the fastest-warming regions on the planet, leaving it disproportionately exposed to frequent and increasingly intense extreme heat events. Scientists point to two key factors driving this accelerated warming: the ongoing melting of the region’s bright snow and ice cover, which previously reflected large amounts of solar energy back into space, and reductions in tiny polluting aerosols in the atmosphere, which also used to reflect sunlight away from the planet’s surface. Some researchers also hypothesize that long-term warming is altering European atmospheric circulation patterns in ways that increase the frequency of the high-pressure systems that spawn heatwaves, though this connection has not been definitively proven.
This summer, European coastal waters are also experiencing record-breaking marine heatwaves, amplified by the recent record-breaking air temperatures above the surface. Unlike air temperatures, which cool relatively quickly after a heatwave passes, ocean water retains heat for far longer periods. This residual ocean heat reduces the cooling effect of coastal sea breezes, creating a feedback loop that can intensify future heatwaves on land.
Climate scientists are unified in their conclusion that human-caused long-term warming has already made extreme heat events like June 2026’s heatwave significantly more intense than similar weather patterns would have been a century ago. “The only way to explain [such strong heatwaves] is to taking into account this [long-term] warming,” Seneviratne explained. “When you have a high-pressure system, this heatwave will tend to be much hotter [now]. This is very well understood.”
The long-term trend of rising average temperatures means that what once qualified as extreme heat in the UK and Europe is quickly becoming the new normal. Only a few decades ago, the UK seeing temperatures rise above 30°C in June was a relatively rare event. Today, it is a routine occurrence. Scientists emphasize that the long-term warming trend does not guarantee every subsequent heatwave will be hotter than the last, or that every summer will be warmer than the previous one. However, as long as global greenhouse gas emissions continue to drive rising average temperatures, summers across the UK and Europe will inevitably grow warmer on average. “Our heatwaves will get hotter and hotter and hotter until we get to global net zero greenhouse gas emissions [and] we stabilise the climate,” Hawkins said.