Europe is baking under a historic heatwave that arrived weeks ahead of schedule, shattering temperature records across a dozen countries and killing dozens of people — and a second round of extreme heat is already building.
Story Highlights
- A powerful heat dome struck Western Europe in late May 2026, pushing temperatures 10–15°C above normal in France, the UK, Ireland, and Portugal.
- Portugal hit 40.3°C (104.5°F), the UK broke its all-time May record twice in two days, and Spain recorded 101 heat-related deaths — the most ever for May.
- The extreme heat was driven by a strong high-pressure system trapping hot air over the continent, a pattern meteorologists call a “heat dome.”
- A second major heatwave began building across Western Europe in mid-June, with forecasters warning of temperatures near 40°C again in France and Spain.
Records Fall Across the Continent
Western Europe experienced an unusually early and intense heatwave from May 21 to 30, 2026. Daily average temperatures in western France, England, and Wales ran more than 10°C above normal. The UK broke its all-time May temperature record at Kew Gardens in London — then broke it again the very next day, reaching 35°C (95°F). Portugal’s town of Mora hit 40.3°C (104.5°F) on May 27, setting a new national May record.[1]
France, the UK, Ireland, and Portugal each recorded their hottest May ever. The World Meteorological Organization confirmed that May 2026 ranked as the second warmest May on record globally across land and sea.[6] The “feels-like” temperature — which factors in humidity, wind, and sun — reached 35°C to 40°C across large parts of Western Europe, creating what scientists classify as “strong” to “very strong” heat stress conditions.[1]
What Is a Heat Dome and Why Does It Matter
The heatwave was driven by a strong high-pressure system that built over continental Europe. That system caused air to sink and compress, which blocked cloud formation and let the sun bake the ground for days without relief. The UK Met Office described the pressure pattern as promoting “prolonged sunshine” and “compressional heating” that pushed temperatures well beyond seasonal norms.[5] This type of weather pattern — often called a heat dome — can persist for days or even weeks.
Scientists note that heat domes are a known weather phenomenon driven by atmospheric circulation. However, formal studies on whether this specific event was made worse by long-term warming trends were still being completed at the time of reporting. What is clear is that the event was extreme by any historical measure. Researchers have found that jet-stream patterns in the upper atmosphere explain up to one-third of the accelerated heatwave trend seen in Western Europe in recent decades.[14]
Deaths, Health Impacts, and a Second Wave Coming
The human toll was significant. Spain recorded 101 heat-related deaths in May — the highest May total since tracking began in 2015. In France, seven deaths were linked to the heat, including five drownings. In the UK, at least 15 people died in water-related incidents during the heatwave, as people rushed to rivers and lakes to cool off.[1] London Underground trains recorded interior temperatures of 34.3°C (93.7°F) during the peak of the heat.
NORTHERN HEMISPHERE STATE OF THE HEAT
21 Jun, Western Europe heat wave is global warming, with France nearing record. So is Southern US, with Texas records; also Brazil and West India. Heat wave in Siberia has Boreal forest looking like record burning. Climate Central's Climate… pic.twitter.com/FWWtHuoxsP— Peter D Carter (@PCarterClimate) June 21, 2026
As if one record-breaking event were not enough, forecasters warned that a second major heatwave began sweeping across Western Europe around June 19–20, 2026. France and Spain faced forecasts of temperatures approaching or exceeding 40°C again. The back-to-back nature of these events — separated by only a few weeks — is what has meteorologists and public health officials on high alert heading into summer. Whether you believe the cause is primarily weather cycles, long-term warming trends, or some combination of both, the practical reality for Europeans is the same: extreme heat is arriving earlier, hitting harder, and demanding better preparation than ever before.
Sources:
[1] Web – Europe braces for prolonged heatwave as temps soar; Amsterdam …
[5] Web – ‘Mind-bogglingly crazy’: Europe’s deadly, early heatwave is … – CNN
[6] Web – Deep Dive: European heat builds while the UK sits on the boundary
[14] Web – Unseasonal May heat wave grips western Europe – DW.com