During 2026, parts of the United Kingdom were severely affected by a series of record-breaking heatwaves, forming the western extent of a broader sequence of extreme heat events across Western and Central Europe.
The first heatwave started on 22 May and saw the country's record for hottest day during May broken on 25 May when was recorded at Kew Gardens in London, surpassing the previous record of set in 1922 by ; this record was broken again when was recorded in the same location the following day. Other records which were broken included the hottest May day in Guernsey, Jersey and Wales, as well as the highest minimum May temperature in the UK. Experts estimated that around 550 people died during this period of extreme heat.
The second heatwave started on 19 June and saw more records broken, including that for hottest day during June when was recorded in Lingwood, Norfolk on 26 June, which is also the fifth hottest day in the UK ever. The previous record for June of was set in 1957 and 1976. A further 2,200 deaths were estimated to have occurred during this heatwave, bringing the total to roughly 2,700.
A third heatwave began on 4 July, with temperatures peaking at in Wisley, Surrey, on 9 July. This marked the first year when temperatures have reached in three separate months, whilst the records for most days reaching both and in a single year were broken at nine and six respectively.
A fourth, shorter heatwave began on 28 July, occurring alongside severely dry conditions which prompted the Environment Agency to declare a drought across more than half of England and all of Wales.
A fifth heatwave began on 2 August, with a sixth slightly longer heatwave beginning on 9 August.
Background The Met Office considers a heatwave to be when temperatures on three consecutive days surpass , depending on the location within the United Kingdom. The UK Health Security Agency (UKHSA) issues heat-health alerts to provide warning when high temperatures are expected to impact the population's health and wellbeing; the core alerting system runs from 1 June to 30 September, with alerts outside of this core period described as "extraordinary".
Late May heatwave
On 22 May, the UKHSA issued yellow heat-health alerts for the East Midlands, East of England, London, South East and West Midlands regions, in place from 9 a.m. that day. These alerts were escalated to amber from 2 p.m. as further yellow alerts were issued for the remaining regions of England; all alerts were set to remain in place until 5 p.m. on 27 May.
The first areas of the country met heatwave conditions on 24 May, when temperature thresholds were reached in eight locations in Essex, London, Oxfordshire and Suffolk. England, Wales and all recorded their highest temperatures of the year so far at in Kew Gardens, in Cardiff and in Armagh; Scotland reached in Edinburgh, just short of a high recorded earlier in May. Jersey's record for the hottest May day ever was broken as temperatures reached in St Helier, breaking the previous record of set in 2003.
Overnight temperatures in Kenley did not fall below , breaking the record for highest minimum May temperature; the previous record of was set in Folkestone in 1944. The record for the hottest May day in the United Kingdom was broken on 25 May after was recorded in Kew Gardens, surpassing the previous record of , which was reached in 1922 and 1944, by a whole ; this also broke the record for hottest bank holiday Monday as it exceeded the recorded on the August Bank Holiday in 2019. Wales also saw its hottest May day on record as temperatures reached at Hawarden Airport, surpassing the previous record of set in Newport in 1944. Northern Ireland and Scotland saw their warmest days of the year so far, with temperatures of and being recorded in Derrylin and Charterhall, respectively. The May record for Jersey was broken again as temperatures reached , whilst a temperature of broke Guernsey's previous record of .
The country saw a tropical night – one where temperatures do not fall below – on 26 May, with a minimum temperature of recorded at Kenley Airfield, breaking the record for highest minimum May temperature again. The heat-health alert in South West England was upgraded to amber, whilst all warnings were extended to 5 p.m. on 28 May. The British record for hottest May day was surpassed again, with temperatures peaking at in Kew Gardens. A temperature of in Bute Park also broke Wales's record again. Records in the Channel Islands were also broken again as temperatures continued to rise for a third consecutive day, with and recorded in Jersey and Guernsey, respectively.
On 1 June, the Met Office said provisional statistics showed that both England and Wales had experienced their warmest springs on record with mean temperatures of and respectively, whilst the UK as a whole saw its third at ; Scotland saw its sixth warmest at and Northern Ireland saw its tenth at . All three months of spring ranked within the country's top ten warmest, with March ranking joint tenth, April seventh, and May joint third, whilst 40 counties saw their warmest spring on record.
Impact An estimate from Imperial College London, the London School of Hygiene and Tropical Medicine and the Met Office published in mid-July placed the number of deaths from the heat between 21 and 29 May at around 550. An interim report on heat-associated deaths by the UK Health Security Agency using a different methodology estimated that there were 753 deaths linked to the May heatwave. Between 24 and 31 May, at least 20 people died in water-related incidents across the country, including 14 children, prompting water safety experts to urge the government to treat drownings as a "public health disaster".
The heatwave disrupted numerous services, including public transport and water supply. South East Water first reported supply issues in the villages of Challock, Charing and Molash on 23 May, with a peak of around 800 properties affected before the issue was resolved on 26 May. Separate issues affected 168 properties in Eastbourne and around 20 homes in Ulcombe, whilst a failed pump disrupted supplies to 64 properties in Radfall. By 27 May, around 18,000 properties were facing water supply disruptions across Kent in areas including Ashford, Maidstone and Whitstable.
Rail transport was severely disrupted, with South Western Railway saying all lines were being affected by heat-related speed restrictions, multiple signalling faults and track defects on 26 May. Heat-related incidents between and disrupted services on some lines between the former and , whilst a problem with equipment at meant trains were unable to call at one of its platforms. Avanti West Coast services were hit by points and signalling failures, blocking some lines at as well as between and , whilst high track temperatures led to speed restrictions between the latter and and Euston. Speed restrictions also affected services between and and , whilst several lines of the London Underground and Overground were disrupted.
Mid/Late June heatwave
On 18 June, the UKHSA issued amber heat-health alerts for the East of England, London, South East and South West regions, with yellow alerts for the East Midlands and West Midlands, in place until 8 p.m. on 23 June. On 20 June, the UKHSA announced that, from 11 a.m. on 22 June, the East and West Midlands would be under amber alerts, with yellow alerts issued for the North East, North West and Yorkshire and the Humber; all alerts were set to remain in place until midnight on 24 June. They announced the following day that the alerts for the North West and Yorkshire and the Humber would be upgraded to amber, with all alerts in place until 11 p.m. on 26 June. On 22 June, they announced that red alerts would be in place for the East Midlands, East of England, London, South East, South West and West Midlands from 1 a.m. on 24 June to 11 p.m. on 25 June, marking only the second time this level of warning has been issued, the first being during the heatwave in July 2022; further amber alerts were issued for the remaining regions of England. These alerts were extended until 11 p.m. on 26 June two days later.
The Met Office issued several weather warnings for extreme heat: an amber warning covered large parts England and Wales from 1 a.m. on 22 to midnight on 23 June; another amber warning covered a larger area for all of 24 and 25 June; a red warning covered parts England and Wales from 9 a.m. on 24 June to midnight on 25 June; an amber warning covered large parts of England all day on 26 June; another red warning covered parts of southern and eastern England from midnight to 9 p.m. on 26 June; and an amber warning covered parts of eastern England from midnight on 27 June to 9 a.m. on 28 June. Since their introduction in 2021, extreme heat warnings are rarely issued, with the first of this heatwave's amber warnings being only the sixth issued, and the red warning the first in Wales and only the second nationally; this heatwave also marked the first time red warnings for extreme heat had been issued on three consecutive days.
On 21 June, the first areas of the country met heatwave conditions as temperatures surpassed for the third consecutive day in Writtle, with temperatures peaking at at Heathrow Airport. The following day the highest temperature was , recorded in Yeovilton. Thunderstorms across parts of southern England that evening prompted a yellow weather warning, with flash flooding, power cuts, travel disruption and several house fires caused by the storms, including one in Bristol that forced the evacuation of multiple homes.
Many parts of the country experienced a tropical night, with the Welsh record for highest minimum June temperature broken in St Athan when readings did not fall below . On 23 June, temperatures peaked at in Wisley, with recorded in Wales as both Scotland and Northern Ireland saw their hottest days of the year so far at in Dyce and in Katesbridge. More areas experienced another tropical night, with the highest overnight low of recorded at RAF Brize Norton. The record for the hottest June day in the United Kingdom was broken on 24 June after was recorded in Gosport, surpassing the previous record of set in 1957 and equalled in 1976. Wales saw its hottest day of the year so far when was recorded at Bute Park in Cardiff. Jersey's record for hottest June temperature was broken when was recorded, surpassing the previous record of set in 2025 by almost ; this is also the second highest temperature ever recorded on the island.
The record for highest minimum June temperature was broken after temperatures only fell to in Cardiff, breaking both the Welsh and UK records, whilst the English record was also broken with a minimum temperature of recorded in Plymouth. On 25 June, the record for hottest June day was broken again as temperatures reached at Yeovilton in Somerset. Wales also saw its hottest June day on record after was recorded at Bute Park, surpassing the previous record of from 2000; Scotland and Northern Ireland saw their hottest days of the year so far at in Threave and in Castlederg. The Channel Islands saw their hottest day on record when was recorded in Jersey, whilst Guernsey also had its hottest day on record at . For the third consecutive day, the record for hottest June day was broken again on 26 June after was recorded at Lingwood in Norfolk. However, the highest temperatures for the other three countries of the UK started to decrease, with Wales seeing in Hawarden, Scotland seeing in Eskdalemuir, and Northern Ireland seeing in Katesbridge.