A powerful heat dome driven by hot air pushing northward from Africa has delivered the most extreme late-May temperatures recorded across Western Europe in living memory, with records tumbling from London to the French Riviera as the final week of May begins.
Forecasters at Severe Weather Europe describe this as the strongest heat dome so far in 2026, with temperatures running 12 to 16 degrees Celsius above long-term seasonal averages. For Monaco and the surrounding region, that means midsummer conditions arriving more than three weeks ahead of schedule.
What is driving the heat
The phenomenon is driven by a subtropical ridge of high pressure building northward from North Africa, trapping a descending air mass beneath it. With vertical mixing suppressed and cloud cover largely absent, intense solar radiation combines with compression to force temperatures upward at the surface — a classic heat dome pattern, but on a scale rarely seen this early in the season.
France’s national weather agency Météo France attributed the event to hot air from Morocco locked under an area of high pressure, warning that Europe can expect such episodes “more and more often, more and more intense, and earlier and earlier.”
Records across the continent
Across southern and southwestern parts of Portugal, Spain, and France, daytime highs climbed between 35°C and 38°C over the weekend. Italy recorded 31–34°C on Sunday, with 30–33°C across Germany, the Alps, and parts of the Balkans.
The UK broke its all-time May temperature record, with 33.5°C recorded at Heathrow near London, and highs of up to 35°C were forecast for Tuesday. More than 20 towns in France also recorded their highest-ever May temperatures.
Spain’s State Meteorological Agency AEMET warned that temperatures described as “extraordinarily high for this time of year” will continue throughout the week, with peaks of 36–38°C forecast for the Guadiana and Guadalquivir regions from Wednesday to Friday.
More records expected this week
Forecasters warn the air mass will intensify further in the coming days. Because the blocking pattern restricts cloud cover and vertical mixing, both daytime highs and overnight lows are expected to challenge historical May records across hundreds of stations throughout Western Europe.
Climate researcher Robert Vautard told Agence France-Presse: “This extension of the heatwave season is entirely characteristic of the effects of climate change. Eventually, we will be seeing similar heat events in April and October.”
For those on the French Riviera this week, the advice is to seek shade during peak afternoon hours, stay hydrated, and expect the kind of heat that normally only arrives in July.
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Photo credit: Cassandra Tanti