In 2023, a series of heat waves impacted Europe. The most significant of which was the named heat wave, Cerberus Heatwave, which brought the hottest temperatures ever recorded in Europe. Starting on 10 July 2023, the record-breaking Cerberus anticyclone affected many European countries, with the effects felt most severely in parts of Southeast and Southwest Europe such as Cyprus, Greece, Italy, and Spain. The private Italian weather website iLMeteo named the extreme weather event after the hound of Hades from Greek mythology, and although some reports link the naming to the Italian Meteorological Society, the society's president said that they "absolutely don't use it".
Several regional temperature records were broken, and the heatwave prompted health warnings and government action in several countries.
According to the British Met Office, 2023 was expected to have more intense heatwaves than those experienced in 2022. In June, the European Environment Agency warned that schools and hospitals were at risk of high temperatures.
Background
On 1 January 2023, at least eight European countries recorded their warmest January day ever: Liechtenstein, the Czech Republic, Poland, the Netherlands, Belarus, Lithuania, Denmark and Latvia. This was attributed to climate change.
Scientists have attributed the 2023 heat waves to human-made climate change. During each day in July 2023, two billion people experience heat conditions made at least three times more likely due to climate change and 6.5 billion people experienced this impact at least one day in this month. The heatwaves caused severe damage in southern US, Southern Europe, South and southeast Asia.
Heatwaves becoming more frequent and intense due to climate change are a big problem for Europe. The heatwaves in the year 2003 killed 70,000 people, while in the record breaking summer of 2022, 61,672 people died. The mortality was 56% higher among women in comparison to men. The countries with the highest rates of mortality were Italy, Greece, Spain and Portugal. According to one climate researcher Hicham Achebak: "The fact that more than 61,600 people in Europe died of heat stress in the summer of 2022, even though, unlike in 2003, many countries already had active prevention plans in place, suggests that the adaptation strategies currently available may still be insufficient,". In the future heat related mortality can be significantly higher. According to NASA senior scientist Katherine Calvin: "Future warming depends on future emissions".
By country
Albania Albania set its all-time high temperature record at in Kuçovë.
Austria
On 18 June, temperatures above were recorded at eight stations in the Ubimet network, reaching in Bludenz and marking the beginning of a heat wave that was expected to peak on 22 June. Prior to 18 June, a temperature of was not recorded at any official station in Austria since the beginning of 2023, marking the country's latest first occurrence of the value in a calendar year since 1990. On 22 June, temperatures of or higher were recorded at eight stations in the Ubimet network, reaching in Bad Goisern am Hallstättersee.
The second heat wave of 2023 was expected to affect Austria between 10 July and 13 July, with maximum temperatures of up to predicted to occur during the first two days. After two days of heavy thunderstorms, temperatures in excess of were expected to return on 14 July and reach as high as in areas north of the Alps on 15 July. During the week starting on 17 July, heavy thunderstorms kept forming in western and southern Austria on a daily basis. They were especially intense in Styria and Carinthia, and also affected parts of Italy, Slovenia and Croatia.
Belgium On 12 June 2023, officials issued a heat wave health warning. The highest temperature was measured on 8 July in Westmalle when it reached .Klimatologisch maandoverzicht meteo.be
Bulgaria Temperatures in Bulgaria reached during the Cerberus heat wave. Temperatures stayed above for more than 2 weeks.
Croatia Temperatures reached by 13 July, sparking a significant wildfire near Šibenik.
Cyprus Temperatures in Cyprus neared inland during the heatwave, with even elevated mountainous areas such as the Troodos region reaching a record-breaking . Government officials issued heat warnings and set up "heat shelters" in various cities.
Czech Republic The Czech Republic experienced the hottest day of the year so far on 15 July. In several places, it was above , the warmest in Plzeň-Bolevec and Řež near Prague, where temperatures reached . Nearly 100 of the 160 or so stations measuring 30 years or more recorded temperature highs for 15 July.
France By 1 June 2023, 50 departments of France were under orange vigilance and 24 under yellow vigilance. At least 80 heat-related deaths were recorded from 7–13 July. The highest temperature was measured on 23 August in Toulouse, when it reached . A report released by Public Health France on February 8, 2024, confirmed that 5,167 people died due to the heat during the summer in France in 2023.
Germany Germany saw warmer than usual temperatures. The German government promised a plan to prevent heatwave deaths. On 22 June, temperatures rose to during the nation's first heatwave of 2023. During a second heatwave, temperatures rose to on 9 July. On 15 July, temperatures reached in Möhrendorf (Bavaria).
On 20 July, the Robert Koch Institute estimated that at least 830 heat-related excess deaths occurred in the Germany between 10 April and 9 July.
Greece
On 14 July 2023, the World Meteorological Organization station in Thiva registered making it the highest temperature in the country for that day. On the same day Athens recorded in the suburb of Filothei. Officials in Athens announced midday closure of the Acropolis. On 15 July 2023, the National Observatory of Athens station in Elafonisi also recorded a maximum temperature of .
On 15 July, five people in Athens Urban Area were reported to have suffered from hyperthermia, while at least 10 more reportedly fainted, though it is not clear how many of them did so due to the heat. The Hellenic National Meteorological Service issued an Orange Warning for Extremely High Temperatures. On that day the highest temperature in the Athens metropolitan area was in Aspropyrgos. On 20 July 2023, a delivery driver in Chalcis died from cardiac arrest, a few hours after he ended his shift. The man was found out to be uninsured and the owner of the grill house was later arrested. He was working for hours outdoors with temperatures exceeding . On 22 July 2023, Kato Tithorea registered making it the highest temperature in the country for that day, while the World Meteorological Organization station in Lefkohori recorded .Lefkochori oscar.wmo.int
On 23 July 2023, the World Meteorological Organization station in Gytheio recorded making it the highest temperature in the country for that dayGytheio oscar.wmo.int while Nea Filadelfeia in Athens recorded . On 26 July 2023, the World Meteorological Organization station in Agia Triada recorded making it the highest temperature in the country for that day.Agia Triada (Greece) oscar.wmo.int
Throughout the prolonged heat wave, wildfires devastated parts of the country, killing at least 28 people, mostly in the Athens metropolitan area and Rhodes.Φωτιά στη Ρόδο: Μαίνεται το μεγάλο μέτωπο - Ανησυχία για τον «ακραίο κίνδυνο» σήμερα protothema.gr (in Greek)
Ireland Met Éireann stated that 2023 had the hottest June on record with an average monthly temperature of greater than 16 °C and a maximum of 28.8 °C at Oak Park in County Carlow on Tuesday 13 June, setting a heat record for 13 June in Ireland.
Italy Since 11 July, at least six men have died after collapsing while working due to the intense heat. Most of Southern Italy saw temperatures above , with temperatures as high as estimated to hit Sicily and Sardinia by the middle of July.
The European Space Agency predicted that temperatures would exceed in Sardinia some time in July. Tourists throughout the country were also observed to suffer from heat stroke, with a British visitor fainting at the Colosseum. It is also expected that an anticyclone dubbed "Charon" originating from North Africa may raise the temperature to above in parts of Italy early in the week beginning 17 July.
On the two main islands temperatures reached their peak on July 24: in Sardinia, despite unofficial higher values having been reached, the highest reliable temperature recorded by a regional station belongs to Bari Sardo with . The same day on the island two national stations recorded their all-time record with in Olbia and in Decimomannu Air Base. In Sicily the highest temperature will be reached by the Syracuse station with , the same weather station that holds the highest official temperature in Europe. The same day the Palermo Astronomical Observatory observed a temperature of , the highest ever recorded in the Sicilian capital city since the beginning of the meteorological data records started in 1791. The heat was infernal and unbearable for practically the entire month, so much that July 2023 was the hottest month of July in Sicily so far: some stations in the Sicilian inland regions such as those of Caltanissetta and Enna recorded 11 consecutive days with maximum temperatures exceeding , as reported by the regional office SIAS (Sicilian agrometeorological information service).
Netherlands From 8 June to 26 June the Netherlands experienced regional heatwaves. On 11 June the temperature reached in Gilze-Rijen and Hoek van Holland, setting a heat record for June 11. Also on 12 June a heat record was broken when the temperature reached in Gilze-Rijen. The unusually high temperatures continued, and on 25 June it was once again hot, with the temperature reaching in Maastricht. After the June heatwaves temperatures went down, however another heatwave took place from 7 July to 12 July. On 8 July the temperature reached in Eindhoven, setting a heat record for 8 July. The highest temperature was measured on 9 July when it reached in Arcen. There was a third regional heatwave in September, with temperatures reaching on 10 September in Eindhoven and Ell, setting a heat record for 10 September in the Netherlands.Temperature map wetterzentrale.de
Norway On 13 July, temperatures of were observed at northern Norway's Slettnes Lighthouse, breaking a record previously held for 80 years. On 15 June the temperature reached in Oslo, setting a heat record for 15 June in Norway.
Romania A first heat wave struck Romania after 3 July, with temperatures exceeding . A second heat wave arrived after 12 July, with temperatures reaching 39 Celsius degrees, prompting Romanian authorities to issue yellow and orange alerts. On 16 July, Elena Mateescu, the director of Romania's National Administration of Meteorology stated this month could be the warmest July in Romania in 120 years. As of 17 July, temperatures are expected to go even higher, eventually surpassing .
Slovenia The first heat wave of 2023 in Slovenia began on 19 June and ended on 23 June, when many parts of the country experienced heavy thunderstorms due to the arrival of a cold front. Between 21 June and 23 June, the Slovenian Environment Agency (ARSO) recorded temperatures in excess of at several stations in their network. The highest temperature during the period was , recorded at the ARSO station at Cerklje ob Krki Airport on 21 June, whilst temperatures at the ARSO station in Dobliče reached on both 21 June and 23 June.
The second heat wave of 2023 in Slovenia lasted from 8 July to 12 July, before heavy rain and high winds affected much of the country on the morning of 13 July. On 10 July, several stations in the ARSO network recorded temperatures between and , reaching as high as in Osilnica, as well as in both Bilje and Podnanos.