In late June and late July 2019 there were two temporally distinct European heat waves, which set all-time high temperature records in Belgium, France, Germany, Luxembourg, the Netherlands, and the United Kingdom.
The first heat wave, in late June, killed over 567 people, and according to meteorologists it was caused by high pressure and winds from the Sahara Desert affecting large parts of the continent. It resulted in record-breaking temperatures for the month of June at many locations. France experienced temperatures in excess of 45 °C (113 °F) for the first time in recorded history. A national all-time record high temperature of 46.0 °C (114.8 °F) occurred on 28 June in Vérargues.
In late July, a second heat wave occurred, during which all-time records were broken by 3 °C (5.4 °F) in Belgium, by 2.1 °C (3.8 °F) in Germany and the Netherlands, by 0.3 °C (0.5 °F) in Luxembourg, and by 0.2 °C (0.4 °F) in the United Kingdom. The deaths of 868 people in France and one person in Belgium were reported, along with thousands of animals when ventilation systems in barns were overwhelmed. Due to high river water temperatures and sluggish flows, particularly in France and to some extent Germany, a number of thermal power stations that use once-through cooling and do not have cooling towers had to reduce output or shut down to avoid breaching environmental limits on river water temperature designed to protect aquatic life.
Meteorological history
The above-normal hot condition in June is caused by an anomalous long-lasting anticyclone in the upper troposphere, which advects warm air from the Sahel and Mediterranean region and enhances incoming solar radiation and surface turbulent fluxes. The anomalous anticyclone results from an unusually-intensified British-Baikal Corridor pattern and a synoptic Rossby wave breaking event over Europe.
The July heat wave was caused by a strong omega block, consisting of hot, dry air from North Africa, trapped between cold storm systems. The high-pressure area of hot air, called Yvonne, stretched from the central Mediterranean to Scandinavia and was pinned between two low-pressure areas, one over western Russia and the other over the eastern Atlantic.
Fatalities
Total excess deaths are estimated to be around 2,500 during the summer months in 2019. Most of these were indirectly caused and were observed in statistical modeling later that year. Based on individual country counts, that figure may be an under estimate. The Dutch government reported 400 excess deaths in the week of the June heat wave, a figure comparable to those recorded during the 2006 European heat wave.
France estimated 1,435 additional deaths due to the heatwave. Public Health England reported 900 excess deaths from the heatwave. The Robert Koch institute reported 500 excess deaths in Berlin alone.
Belgium reported at least 716 excess deaths during the summer.
By country
Austria
In June heat records were broken, on 30 June the temperature reached 38.5 °C (101.3 °F) in Innsbruck. This was a heat record for June in Austria, and also the highest temperature measured during the heatwaves.
Belgium
Belgium recorded three consecutive days exceeding 30 °C (86 °F); 25 June was the hottest day during this period, with many places exceeding 32 °C (90 °F) and other places nearly reaching 35 °C (95 °F).
During the period of hot weather, environmental officials warned of poor air quality levels, which would especially affect the young, elderly and people with respiratory illnesses. It also affects small countries that rely on tourism as their main source of income.
On 24 July, the highest ever recorded temperature in Belgium was measured, reaching 40.2 °C (104.4 °F) in the town of Angleur, exceeding the previous record of 38.8 °C (101.8 °F), reached in 1947. On the same day, passengers were evacuated from a Eurostar train that had broken down between Halle and Tubize, as many began to fall ill due to the extreme temperatures. On 25 July, the national record was broken again, reaching 41.8 °C (107.2 °F) in Begijnendijk (Flemish Brabant). One death was reported.
The official KMI weather station in Uccle reported a maximum temperature of 39.7 °C (103.5 °F), while many other weather stations, some even close to the North Sea, reported temperatures in excess of 40.0 °C (104.0 °F).
Czech Republic
The temperature record for June was recorded in Doksany and was 38.9 °C (102.0 °F). High temperatures also complicated rail transport in the Czech Republic.
Denmark
On 22 July 2019 the DMI issued a warning for high temperatures possibly up to 35 °C (95 °F). On 24 July, the temperature reached 30.9 °C (87.6 °F) in Åbenrå, Svendborg and Nykøbing Falster.
On 25 July the temperature reached 32.0 °C (89.6 °F) in Vordingborg & Holbæk. Temperatures for that day were forecasted up to 35 °C (95 °F), but due to afternoon thunderstorms the temperature only reached a maximum of 32.0 °C (89.6 °F).
Finland
On 28 July, Helsinki recorded a temperature of 33.2 °C (91.8 °F), breaking the city's previous record. On the same day, 33.7 °C (92.7 °F) was recorded in Porvoo.
France
France was one of the most affected countries from the heatwave, with much of the country exceeding 32 °C (90 °F) on 26 June. Météo France issued an Orange Alert for much of the country due to exceptionally hot temperatures, excluding coastal regions, e.g. Brittany and the northern part of Hauts-de-France. Four departments of France were put on Red Alert: Bouches-du-Rhône, Gard, Hérault and Vaucluse. Owing to building codes with old structures common across the country, numerous buildings in France lack air conditioning.
The French Government acted more proactively for the heat wave in light of its failings during the 2003 European heat wave. 15,000 people died during that event in France. Approximately 4,000 schools closed nationwide. Authorities in Paris opened public cooling rooms. Parks and pools extended operation hours in multiple cities. Museums with air conditioning allowed free entry for all people.
France observed temperatures in excess of 45 °C (113 °F) for the first time in recorded history. A national all-time record of 46.0 °C (114.8 °F) was recorded by a staffed weather station in Vérargues on 28 June, verified by Météo France on 19 July. Earlier, the highest temperature considered to have been reliably recorded during the heat wave was 45.9 °C (114.6 °F) by an automatic weather station in Gallargues-le-Montueux, also on 28 June. These exceeded the previous record of 44.1 °C (111.4 °F), recorded in Conqueyrac and Saint-Christol-lès-Alès.
Twelve other locations observed temperatures above the previous record high. Villevieille experienced temperatures of 45.1 °C (113.2 °F) on this day. Numerous records were broken along the Mediterranean coastline. Montpellier observed a temperature of 43.5 °C (110.3 °F), shattering the previous all-time by 5.8 °C (10.4 °F). Nantes and Bourges saw their highest low-temperature ever during the overnight of 27–28 June at 24.7 °C (76.5 °F) and 23.8 °C (74.8 °F), respectively.
Five people died nationwide: four from drowning and one from heat stroke. Police noted an increase in instances of illegal fire hydrant openings. A six-year-old child was hospitalised in critical condition after being hit by a stream of water from an illegally opened hydrant. Hospitals reported a significant increase in cases of cramps, dehydration, dizziness, and heart conditions.
In July 2019, France experienced its second heat wave in less than a month, beating several regional and national temperature records. In the previous month, a national record temperature of 46.1 °C (115.0 °F) was measured in the southern commune of Gallargues-le-Montueux. More than 50 French cities exceeded their previous high temperature records in this heat wave.
On 23 July 80 departments of France were included in an orange heat wave alert by Météo-France, and 20 departments were included in a red alert the next day. On 24 July, a temperature of 41.2 °C (106.2 °F) was registered by Météo-France in Bordeaux, breaking the city's previous record of 40.7 °C (105.3 °F) in 2003. Similarly, on 25 July, a temperature of 42.6 °C (108.7 °F) was recorded in Paris, also breaking the city's previous record of 40.4 °C (104.7 °F) in July 1947.
On the night of 24–25 July, France saw its hottest night since records began, as the whole country averaged an overnight low of 21.4 °C (70.5 °F), exceeding the record from the 2003 heat wave. Bordeaux saw an overnight low of 26.8 °C (80.2 °F), beating the previous record of 25 °C (77 °F, 2006); Lille saw 23.2 °C (73.8 °F), exceeding the July 2007 record of 22.5 °C (72.5 °F). Lille also saw a high of 41.5 °C (106.7 °F) the following day, above the record of 37.6 °C (99.7 °F) that had been set the previous year.
On 25 July, the chief architect of the Notre-Dame de Paris cathedral told media that he feared that the heat wave could cause the cathedral's vaulted ceilings, damaged in an April 2019 fire, to collapse. While he indicated the stone walls were still stable for the time being, he explained that the walls were still saturated with water sprayed by firefighters during the blaze, and rapid drying from the extreme temperatures could adversely affect the stability of the structure.
Two nuclear reactors in southwest France were shut down and the output of six reactors were curtailed to avoid breaching environmental limits on the temperature of the rivers they use for cooling water. This reduced French nuclear power generation by around 5.2 gigawatts at a time of increased electricity demand due to the use of cooling devices.
According to the French Ministry of Health, 567 were reported to have died during the June heat wave, and 868 people died as a result of the July heat wave.
Germany
Most of Germany recorded temperatures exceeding 32 °C (90 °F) on 26 June as well as large parts of the country exceeding 35 °C (95 °F). Temperatures as high as 37.5 °C (99.5 °F) were recorded in Berlin-Tempelhof, and Brandenburg had temperatures reaching 38.6 °C (101.5 °F), exceeding the previous June record of 38.2 °C (100.8 °F) recorded in Frankfurt. Nationwide, the average temperature for all of June reached 19.8 °C (67.6 °F), marking the warmest June in 140 years of record-keeping.
Four people died from drowning nationwide.
On 25 July, a temperature of 42.6 °C (108.7 °F) was recorded in Lingen, Lower Saxony. This beat the record for the highest ever temperature recorded in Germany, following its previous record of 40.5 °C (104.9 °F) measured a day earlier. Twenty-five weather stations in the country reported temperatures of 40 °C (104 °F) or higher on 25 July. Prior to this heat wave, the highest recorded temperature in Germany was 40.3 °C (104.5 °F) in Kitzingen in 2015.
At the end of the heat wave, on the evening of 26 July, a maximum purple alert for storms was issued for three districts (Landkreise) of the Land Baden-Württemberg, namely Freudenstadt, Böblingen and Calw.
Greenland
After the heat wave ended in mainland Europe, the mass of warm air traveled north to Greenland, causing a heat wave that led to a melting of some 197 gigatonnes (217 billion short tons) of ice in July. The melting was forecast to peak on 1 August. For comparison, the entire melt season in 2012 caused 290 gigatonnes (320 billion short tons) of ice loss. A record 56.5 percent of Greenland Ice Sheet was showing signs of melting on 31 July. US National Snow and Ice Data Center estimated ice loss during the first week of August at 11–22 gigatonnes (12–24 billion short tons) per day with a total loss of 230 gigatonnes (250 billion short tons) for the melt season to date.
A wild fire which has been burning near Sisimiut since early July necessitated dispatching firefighters from Denmark, as the fire was endangering inhabited areas and had the potential to continue burning through the winter. Forest fires are exceedingly rare in Greenland.
Italy
By 28 June, Italian authorities placed 16 cities under high alert for dangerous temperatures. Civil security services distributed water to tourists visiting Rome.
A 72-year-old man died of heat stroke in the Milano Centrale railway station.
Luxembourg
On 25 July, a red alert for extreme heat was put in place for the entire country by Meteolux. The same day, a temperature of 40.8 °C (105.4 °F) was measured in Steinsel, the highest ever recorded in the country, beating the record of 40.5 °C (104.9 °F) set in Remich in 2003.
The high heat and dry conditions caused several fires during the heat wave. On 24 July, a fire broke out near Schumannseck, and hay bales caught fire in a field. On 25 July, a bush fire occurred in Hamm, and a fire truck exploded when it became engulfed in flames whilst attending the scene.
Netherlands
On 25 June, much of the inland areas of the Netherlands exceeded 32 °C (90 °F). The KNMI issued a code yellow warning for large parts of the country due to the heat, and RIVM also put National Heat Plans into force in areas issued under code yellow.
De Bilt, where the headquarters of the KNMI is located, recorded a temperature of 33.2 °C (91.8 °F), and parts of Uden and Gelderland recorded temperatures as high as 36 °C (97 °F).