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. 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 .
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 35.7 °C during the nations first heatwave of 2023. A second period of high temperatures in early July lead the temperatures to rise to 38 °C on 9 July. On 15 July the temperature reached 38.8 °C 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 . On 23 July 2023, the World Meteorological Organization station in
Gytheio recorded making it the highest temperature in the country for that day 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. Throughout the prolonged heat wave,
wildfires devastated parts of the country, killing at least 28 people, mostly in the
Athens metropolitan area and
Rhodes.
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.
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. The third heat wave to affect Slovenia in 2023 began on 15 July and ended on 19 July, reaching its peak when temperatures between and were recorded in the lowlands on 17 July. The same day, temperatures at the ARSO station in Dobliče reached , which was the highest officially recorded temperature in Slovenia in 2023. A further three stations in the ARSO network recorded temperatures of up to during the third heat wave, and the value of was reached or exceeded at a further seven stations in the ARSO network. Agriculture was heavily disrupted. In June and July three people died by heatstroke. According to Carlos III Health Institute 659 mainly elderly people died between 8 July and 17 July due to heat. Between 21 June and 8 July 309 excess deaths were recorded, bringing the total to 968.
Switzerland During the summer Switzerland experienced multiple heatwaves in July, August and September. The highest temperature measured during the heatwaves was in
Geneva on 24 August. Four per cent of its total glacier volume disappeared.
United Kingdom The United Kingdom did not experience heatwaves as defined by the
Met Office during the meteorological summer. Nevertheless, the mean temperature in June was , the warmest since records began in 1884, and 0.9 °C higher than the previous record, set in 1940 and 1976. The highest temperature was , recorded in
Chertsey on the 10th and
Coningsby on the 25th, and records were also broken in 72 of the 97 areas where temperature data are collected. A yellow heat alert was issued for London, the east and west Midlands, and the east, south-east and south-west. A yellow alert was also issued for
Northern Ireland on 12 June. A low pressure system over the country produced cooler, wetter weather in July and August.
September 2023 In September, the UK was hit by a record-breaking heatwave, which lasted eight consecutive days. On 4 September, the
UK Health Security Agency (UKHSA) issued a yellow heat-health alert from 2 p.m. that day to 9 p.m. on 10 September for all areas of England except the North East. This was increased to an amber heat-health alert on 5 September for all areas of except the North East, which received a yellow alert. On 7 September, the record for most consecutive September days where temperatures reached , which was previously five days, was broken. Also on 7 September, a provisional temperature of was recorded in
Wisley,
Surrey, which was the hottest day of the year until 9 September. The previous record for the greatest number of September days where temperatures have reached or more was five, set in 1911, however it was broken on 9 September. On 8 September, the record for highest September temperature in Northern Ireland was broken, with recorded in
Castlederg,
County Tyrone. The previous record, set on 1 September 1906, was in
Armagh. On 9 September, a temperature of was recorded at
Heathrow, making it the hottest day of the year. Kew Gardens later recorded , making 9 September 2023 London's second-hottest September day ever recorded. All operational London stations broke their previous records. Stations that have achieved higher temperatures in the past like
Gravesend,
Kent and
Hampstead in London may have recorded even higher temperatures were they still operational during the heatwave. On 10 September, the final day of the heatwave, temperatures exceeded for the seventh consecutive day, peaking at at
Brogdale, near
Faversham in
Kent. This would also make September 10 the hottest day of 2023. As the heatwave broke, a yellow weather warning for thunderstorms was put in place for most Northern Ireland and parts of northern England and Wales and southern Scotland. ==Highest temperature by country==