July 2019 European heat wave

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 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 for the first time in recorded history. A national all-time record high temperature of occurred on 28 June in Vérargues.

In late July, a second heat wave occurred, during which all-time records were broken by in Belgium, by in Luxembourg, by in Germany and the Netherlands and by 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, and the Robert Koch institute reported 500 excess deaths in Berlin alone.

The June heat wave was directly implicated in the deaths of at least 15 people. Five died in France, four in Germany, three in the United Kingdom, two in Spain, and one in Italy. Nine of these were drownings, attributed to people cooling down, and another involved an exhausted farm worker who went unconscious after diving into a pool. The three who died in hot air were aged 72, 80 and 93. Approximately 321 million people were otherwise affected by similar temperatures in the same countries.

By country

Belgium

Belgium recorded three consecutive days exceeding ; 25 June was the hottest day during this period, with many places exceeding and other places nearly reaching .

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 in the town of Angleur, exceeding the previous record of , 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 in Begijnendijk (Flemish Brabant). One death was reported.

The official KMI weather station in Uccle reported a maximum temperature of , while many other weather stations, some even close to the North Sea, reported temperatures in excess of .

Czech Republic

The temperature record for June was recorded in Doksany and was . High temperatures also complicated rail transport in the Czech Republic.

Finland

On 28 July, Helsinki recorded a temperature of , breaking the city's previous record. On the same day, was recorded in Porvoo.

France

France was one of the most affected countries from the heatwave, with much of the country exceeding 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