Last Updated on 9 hours ago by TodayWhy Editorial
Germany and much of Europe are sweltering through their second major heatwave in barely a month, with temperatures running 14 to 18 degrees Celsius above normal for late June in some areas. France, Spain, Switzerland and the UK have all broken June temperature records this week, and the German Weather Service (DWD) has issued extreme heat warnings as the hot air mass pushes east toward Germany, Poland and the Alpine region over the coming days. So what’s actually driving this, and why does it keep happening?
A “heat dome” parked over Western Europe
Meteorologists point to a phenomenon called a heat dome: a large, stationary area of high pressure that traps hot air beneath it like a lid. This one originated as a surge of hot, dry air pulled north from the Sahara, then got stuck in place over Western Europe rather than moving through, as weather systems usually do. Under a heat dome, air sinks and compresses, which heats it further and keeps skies clear and cloudless — ideal conditions for temperatures to climb day after day with little relief, especially overnight.
Video: Red heat alerts issued as Europe hit by heatwave
Why the heat won’t move on: the “omega block”
What makes this particular heatwave so persistent is the broader jet stream pattern holding it in place, known as an omega block, named for the shape it traces across the upper atmosphere — a tall ridge of high pressure flanked by two dips, resembling the Greek letter Omega. This configuration effectively jams the normal west-to-east flow of weather systems across the continent. Instead of the heat dome drifting away after a few days, as a typical summer warm spell would, the omega block keeps it locked in place for over a week, allowing temperatures to compound rather than reset.
How extreme the numbers actually are
The scale of the records broken this week is unusual even by the standards of a warming climate. France recorded its hottest day in history, with a national average temperature of nearly 30 degrees Celsius and dozens of towns hitting all-time June highs above 43 degrees. The UK saw its warmest June day on record at roughly 36 to 38 degrees Celsius, breaking a mark that had stood since 1976. Switzerland logged its hottest June temperature ever, and Spain and Portugal both pushed toward 44 to 45 degrees Celsius at the core of the heat dome. Germany, sitting further from that core, has so far seen temperatures in the high 30s, with the DWD warning that more than 70 million people across the country will experience temperatures above 30 degrees Celsius as the heat shifts eastward this weekend.
Video: Europe grapples with unprecedented heat wave
Why Germany and Northern Europe are catching the “second wave”
Heat domes don’t stay still forever, and as the upper-level ridge driving this one expands and shifts, the most intense temperature anomalies are moving eastward across the map — from their original stronghold over Iberia and France toward Germany, Denmark, Poland, the Baltic states and the Alpine region. That shift explains why the worst of the heat hit France and Spain earlier in the week while Germany’s most extreme temperatures are still building. The DWD has forecast that conditions will intensify over the weekend as the heat dome’s core moves over Central Europe.
Why this keeps happening earlier in the year
Europe’s hottest stretch of summer normally arrives in mid-to-late July, roughly a month after the summer solstice. This is now the second severe heatwave to hit the continent since late May 2026, and historical records suggest only one other major European heatwave has arrived this early since 1950. Scientists describe Europe as the world’s fastest-warming continent, heating at roughly twice the global average rate, which is shifting the timing and intensity of these events. A scientific study of a comparable heatwave that hit southeast England in June 2025 found that, without the influence of human-caused greenhouse gas emissions, an event of that severity would be expected only once every 50 years — underscoring how much more frequent these episodes have become.
Video: France records hottest night and day as Europe heatwave spreads
Why the consequences go beyond discomfort
The current heatwave has already proven deadly in parts of Western Europe, particularly France and Spain, where authorities have linked dozens of deaths to the extreme heat, including drownings as people sought relief in rivers and lakes, and heatstroke among elderly residents. Health officials note that only about one in five European homes has air conditioning, and that much of the continent’s older housing and infrastructure was originally built to retain heat through cold winters rather than dissipate it during summer extremes — a mismatch that makes prolonged heatwaves particularly dangerous as they become more common. Beyond public health, the sustained heat has also strained electricity grids as air conditioning demand spikes, dried out soil in ways that raise wildfire risk, and in some regions pushed river water temperatures high enough to complicate cooling operations at power plants.
Frequently Asked Questions
What is causing the June 2026 heatwave in Europe?
A heat dome of hot, dry air originally pulled north from the Sahara has become trapped over Western Europe by a jet stream pattern called an omega block, which prevents the usual west-to-east movement of weather systems and keeps the heat locked in place for an extended period.
Why is Germany experiencing heat later than France and Spain?
The heat dome’s core began over Iberia and France before expanding and shifting eastward. As that shift continues, the most intense temperatures are moving toward Germany, Poland, Denmark and the Alpine region.
Is this heatwave linked to climate change?
Scientists say Europe is warming at roughly twice the global average rate, and research on a comparable 2025 heatwave found that such intense heat events would be far rarer without the influence of human-caused greenhouse gas emissions.
Why are heatwaves like this so dangerous in Europe specifically?
Only about 20 percent of European homes have air conditioning, and much of the continent’s housing and infrastructure was built to retain heat during cold winters rather than release it during extreme summer heat, making prolonged heatwaves especially hazardous.