While Europe is no stranger to intense summer heat, the end-of-May 2026 heatwave was something else! The astonishing intensity of the heat dome and its surface heatwave have caught communities off guard. A massive and persistent high-pressure system trapped a hot air mass that had advected up from North Africa over Western and Central Europe.
In a matter of days, the calendar month of May went from below-average to other extremes. A large part of the continent went straight into the punishing heat extremes of mid-July.
Recent studies have found that Europe is currently warming at roughly twice the global average rate, and in the last week of May, rapid warming and an intense heatwave served as a stark, early-season demonstration of that trend.
This heatwave was particularly impressive because it obliterated historical temperature records. Typically, they are broken by fractions of a degree, but this week, they were literally demolished by whole numbers.
Before we dig into the details about this historic unusually early-season heatwave in Europe, lets examine what is the main driver behind these extensive warm waves and heatwaves in general.
What is a Heat Dome?
When significant, record-breaking heatwaves occurred in Europe, the United States, and Canada in the past, the Heat Dome was a contributing factor. The heat dome is usually the dominant feature of summer weather patterns on both continents.
We refer to this phenomenon as a heat dome when extremely high temperatures develop. Here’s how it works and why understanding it on a broader scale is essential.
The upper-level ridge pattern, or very warm air mass in the higher altitudes, also known as the Upper High (or blocking High), usually forms the heat dome. This weather pattern brings high, and sometimes record-breaking, temperatures to the region below.
This term is used when a broad area of high-pressure air parks over a large portion of the continent. If the event is remarkably stable and extreme, it usually lasts several days or weeks.
The heat dome works like a lid on a pot. The extensive dome traps warm air at all levels underneath, with layers sinking toward the ground. Therefore, the air mass becomes anomalously warm at the lowest elevations and extremely hot near the surface.
How does a heat dome impact the life underneath?
Excessive heat in heat domes can significantly impact human health and be dangerous to particularly vulnerable populations, such as elderly individuals, children, and those with pre-existing health conditions that can be worsened by extreme heat.
Due to prolonged exposure to high temperatures, construction workers, farmers, and other long-hour outdoor workers are at increased risk of heat-related illnesses. People living in poverty are also more susceptible to the fatalities of heat domes, as their houses are often built with heat-trapping surfaces such as concrete and asbestos.
Heat exhaustion occurs with prolonged exposure to high temperatures. It leads to dehydration, dizziness, and, in more severe cases, heat exhaustion can progress to heat stroke.
High relative humidity during a heatwave can also significantly affect the body. For this reason, we use a Heat Index to represent the perceived feel of scorching-hot temperatures and high humidity. It illustrates the natural relationship between temperature and humidity.
Ireland, Wales, and the UK
Ireland
Shannon Airport Co., Clare reported 30.6 °C on Tuesday, May 26th, 2026. This is the new national heat record for May in Ireland.
Previous records were also shattered in many other parts of Ireland and across the Channel Islands. Oak Park, Co. Carlow, and Gurteen, Co. Tipperary, recorded 29.7 °C while Athenry, Co. Galway, reported 28.7 °C.
England
England has literally destroyed its previous national heat records for May, and it happened over multiple days. The new national record has been set at 35.1 °C, observed at the London-Kew Gardens.
With Kew Gardens recording 35.1 °C, it also broke its previous May record from 1922 by nearly 5 °C and also shattered its June maximum temperature record set in 1976 by 0.5 °C. This just shows how unprecedented this heatwave was.
This was also the earliest 35 °C ever recorded in the UK on record. The previous record was June 26th, 1976.
Wales
Wales also obliterated its national heat record with a temperature of 32.9 °C in Cardiff-Bute Park on Tuesday, May 26th, 2026.
Astonishing Tmax also at the Jersey island. Jersey Airport reported ️34.1 °C, while 34.2 °C was recorded at the Saint Savior – Maison St Louis Observatory. Guernsey Airport on the island of Guernsey also surpassed the 30-degree mark, reaching 31.5 °C on May 27th, 2026.
In addition, the UK has also recorded its new highest daily minimum temperature in May. The temperature didn’t fall below 21.3 °C overnight at Kenley Airfield, making it a so-called ‘tropical night’ (where the night temperature does not fall below 20 °C).
Remarkably, the same record was broken a day earlier, on May 25th. Camborne also holds the unofficial record for the highest UK May minimum temperature, 21.4 °C, but it has yet to be confirmed. This is a few degrees above the old UK record of 18.9 °C set in 1947.
France
The heat reached unprecedented levels in France this Thursday, May 28th, 2026. Unofficial reports from multiple weather stations exceed the previous national monthly record for May, set at 37.0 °C in Sollacaro, Corsica, on May 25th, 2009.
- 37.8 °C in Angoulême-La Couronne (Charente)
- 37.6 °C in Narbonne (Aude)
- 37.4 °C in Perpignan (Pyrénées-Orientales)
Since the start of the current heatwave, more than 1,350 heat records have been broken across the entire French network. This has never been seen before. All-time highs for May have been smashed in Bordeaux, Perpignan, Bergerac, Nimes, Toulouse, Montpellier, to name a few.
All the records are awaiting final confirmation by experts from Meteo France.
Brittany, NW France
Below are the 10 highest temperatures recorded at Rennes-Saint Jacques Airport, Brittany, France, since 1945. The previous record high temperature of 30.8 °C, set from 1947 to 1953, has been surpassed multiple times this week.
Note that, with the exception of the Perros-Guirec and Île de Batz stations, all peak temperature records have been widely surpassed in Brittany during this heatwave.
Brest has broken its monthly temperature records for both minimum and maximum temperatures this week. The daytime peak reached 33.5 °C on Tuesday, 4 °C above the previous record of 29.5 °C observed on May 26th, 2017.
On Wednesday, May 25th, 2026, Brest also shattered its highest nighttime minimum temperature, reaching 19.3 °C, surpassing the previous record of 18.7 °C set on May 26th, 2017.
In addition, Thursday marked the fourth consecutive day with a Tmax of 30 °C or higher, which had only happened twice in 80 years (in August 1955 and June 1976, according to Météo-France historical data).
Luxemburg
Luxemburg has also set its new heat record for May. It was 33.6 °C in Reckange on May 27th, 2026.
Andorra
Borda Vidal (864 m ASL), Andorra, recorded 33.1 °C, tying its May national record at the same weather station as in May 2022.
The report has been confirmed by the National Meteorological Service of the Government of Andorra. Multiple stations surpassed 30 °C, with elevated stations Comella (1.225 m) and the Roc de St. Pere (1.113 m), where the peak of 31.1 °C was recorded.
Spain and Portugal
Portugal
Portugal was the first European country to reach 40 °C in 2026. On May 26th, a new national record was set with 40.3 °C in Mora and 40.1 °C in Alvega, Portugal.
The previous May record was 40.0 °C, observed in Pinhão (1973) and Beja (2015).
Spain
More than 200 stations have obliterated their monthly records across Spain as well. On Wednesday, May 27th, the standout was 36 °C in Zamora, Spain. This temperature mark was reached for the first time in the spring in this city. Zamora has a data series that spans over a century. The previous record, 35 °C, was recorded last year.
35.0 °C was recorded in Salamanca, also the new record for May. 33.5 °C also shattered its old May record in Foronda-Txokiza, Spain, on the 27th. Tortosa reached 37.3 °C, setting a new May record in its more than 100-year data record (previous record was 36.1 °C in 2024).
A new maximum temperature record for May was also reported in Santander: 37.1 °C on May 26th. The previous record dated back to 1964, when 36.8 °C was observed.
A windy night in Portbou, Spain, has set a new record for the highest minimum night temperature in Catalonia. It never got below 28.0 °C on May 28th, 2026. The previous record was 26.8 °C on May 29th, 2001.
Austria
A new national temperature record was also set in Austria, with 32.7 °C recorded in Lienz. This marks the hottest day recorded in the country in May in more than 200 years.
Many other stations also broke their monthly records across the country.
Slovenia
Multiple weather stations in Slovenia have surpassed their May monthly records as well.
- 33.5 °C in Cerklje ob Krki (previous record 33.2 °C on May 27th, 2008)
- 33.1 °C in Litija (previous record 32.4 °C on May 27th, 2008)
- 33.0 °C in Gačnik (previous record 32.7 °C on May 27th, 2008)
- 32.5 °C in Marinčna vas (previous record 32.0 °C on May 27th, 2008)
- 32.2 °C in Ptuj (previous record 32.0 °C on May 27th, 2008)
- 32.1 °C in Kočevje (previous record 31.5 °C on May 25th, 2009)
- 31.7 °C in Šmartno pri Slovenj Gradcu (previous record 31.6 °C on May 27th, 2008)
- 30.4 °C in Rateče-Planica (previous record 29.3 °C on May 30th, 2008 – this was the first time ever above 30 °C during May)
- 30.2 °C in Babno Polje (previous record 30.0 °C on May 25th, 2009)
Italy
Here are some of the maximum temperatures on 27th and 28th May across Italy.
- 36.1 °C in Ferrara
- 35.9 °C in Napoli/Capodichino
- 35.6 °C in Piacenza
- 35.2 °C in Milano / Linate
- 34.9 °C in Marina di Ginosa
- 34.8 °C in Bologna / Borgo Panigale
- 34.7 °C in Bolzano
- 34.6 °C in Decimomannu
- 34.5 °C in Verona / Villafranca
- 34.4 °C in Orte
- 34.4 °C in Novara / Cameri
- 34.2 °C in Firenze / Peretola
* Note that some data are still being reported, and records for the countries may be updated in the coming days with final, official reports by the national weather services. We will update accordingly.
Stay tuned for the updates.
Windy, Pivotal Weather, and WXcharts provided images used in this article.
See also:
Heat Dome Forecast: Europe Braces for Record-Breaking Late May Heatwave