UK Heatwave 2026
The United Kingdom is in the grip of its most dangerous heat event since July 2022. On June 22, 2026 — yesterday — the Met Office issued a Red Extreme Heat Warning covering parts of central and southern England and Wales, Wednesday 24 June to Thursday 25 June, with temperatures forecast to reach 38°C and potentially exceed the UK June record of 35.6°C set in 1976. The forecast peak comes with a factor entirely absent from 2022: exceptional humidity, with dew points reaching approximately 22°C on Wednesday and Thursday — compared to single figures during the July 2022 record event. Met Office Deputy Chief Forecaster Mark Sidaway stated: “Red warnings are reserved for the most severe events and we’re expecting severe and significant impacts — with health impacts likely for many, even beyond those normally more vulnerable to the heat.” This June 2026 event follows a record-breaking May 2026 heatwave that began on 22 May 2026, during which Kew Gardens, London reached 35.1°C on 26 May — smashing the previous UK May record of 32.8°C set in 1922 by a full 2.3°C. Together, the 2026 heatwaves represent a statistical acceleration of heat extremes that climate scientists had modelled but hoped would take longer to arrive.
2026 has provisionally recorded the hottest spring temperature on record, following four heatwaves in Summer 2025 and the warmest and sunniest spring on record in 2025. Met Office Chief Scientist Professor Stephen Belcher CBE stated: “Human induced climate change has made events like this more likely and more intense. To see temperatures like this in the UK in June is sobering.” The UKHSA has issued heat-health alerts continuously since May, with Amber and Red alerts covering wide swaths of England and Wales. Close to 3,000 excess deaths were recorded during five 2022 summer heat episodes in England — the highest since the Heatwave Plan for England was introduced in 2004. With June 2026 combining 2022-level temperatures with significantly higher humidity — reducing the body’s ability to cool through sweating — health authorities are warning that the risk extends well beyond the elderly and vulnerable.
Interesting Facts on UK Heatwave Statistics 2026
| Fact | Figure |
|---|---|
| Met Office warning level issued (June 22, 2026) | Red Extreme Heat Warning |
| Red warning period | Wed 24 June 09:00 – Thu 25 June 21:00 |
| Peak temperature forecast (Thursday 25 June) | 38°C |
| Current UK June temperature record | 35.6°C (Southampton 28 June 1976 / Camden Square 29 June 1957) |
| Likelihood of June record being broken | “Very likely” — Met Office June 24, 2026 |
| Dew point forecast Wed–Thu | ~22°C (vs single figures in July 2022) |
| Tropical nights forecast | Widespread — temperatures not dropping below 20°C |
| Wales provisional overnight record (June 23) | 20.3°C at St Athan, South Glamorgan |
| May 2026 heatwave peak (Kew Gardens, 26 May) | 35.1°C — new UK May record |
| Previous UK May record (broken 25 May 2026) | 34.8°C at Kew Gardens (breaking 32.8°C set in 1922) |
| Margin by which May record was broken | +2.3°C |
| May 2026 heatwave start date | 22 May 2026 |
| Water-related deaths during May 2026 heatwave | At least 15 (9 children) |
| Properties without water supply at peak (May, Kent) | ~18,000 |
| UK all-time temperature record | 40.3°C — Coningsby, Lincolnshire, July 19, 2022 |
| Previous UK record (before 2022) | 38.7°C — Cambridge, July 2019 |
| Excess deaths during 2022 summer heatwaves (65+, England) | 2,803 (ONS/UKHSA) |
| Excess deaths peak day rate (July 2022) | 253 per day (17–20 July) |
| Number of heatwaves declared in Summer 2025 | 4 |
| Heatwave frequency — Met Office annual estimate | 4–10 per year |
| Climate change impact on extreme heat likelihood (UK) | 10x more likely (Met Office) |
| RAC breakdown increase (24 June 2026) | +10% above normal for same Tuesday period |
Source: Met Office Red Extreme Heat Warning press release, June 22, 2026; Met Office Red Warning updated June 24, 2026 (metoffice.gov.uk); Met Office May 2026 record press release, May 25–26, 2026; Wikipedia — May 2026 United Kingdom Heatwave (updated June 24, 2026); ONS/UKHSA Excess Mortality During Heat-Periods England 2022 (ons.gov.uk); House of Commons Library — Heatwaves in the UK (updated June 2026); RAC Drive — UK Heatwaves (updated June 24, 2026); Wikipedia — 2022 United Kingdom Heatwaves
The Red Extreme Heat Warning covering Wednesday and Thursday this week is only the second Red heat warning ever issued by the Met Office — the first was for 18–19 July 2022, when 40.3°C was recorded. What distinguishes the June 2026 event from all previous UK heat events is the humidity factor. Dew points forecast to reach approximately 22°C on Wednesday and Thursday compare to the July 2022 heatwave, when dew points were only in single figures — highlighting how much more oppressive this heatwave will be. The body cools primarily through sweating; when the air is already saturated with moisture, sweat cannot evaporate, and body temperature rises rapidly. Heat stress becomes dangerous even for physically fit and healthy adults under these conditions — exactly why the UKHSA escalated its alert framework and the Met Office used the phrase “health impacts likely for many, even beyond those who are normally more vulnerable.”
The 15 water-related deaths during the May 2026 heatwave — nine of them children — are a tragic illustration of how quickly public response to warm weather outpaces safety awareness. These deaths prompted the Royal Life Saving Society to issue warnings that warmer weather sees an increase in water safety incidents as more people seek cooling near rivers, lakes, and coastal water. Cold water shock remains lethal regardless of air temperature: sea and inland water temperatures in May and June run dramatically colder than air temperatures, and sudden immersion triggers a breathing and cardiac response that can incapacitate even strong swimmers.
May 2026 UK Heatwave Temperature Records
May 2026 Heatwave Peak Temperatures (Met Office Records)
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Kew Gardens (26 May) |████████████████████████████████████████████████| 35.1°C — UK May record
Kew Gardens (25 May) |█████████████████████████████████████████████ | 34.8°C — broke May record first
Cardiff/Bute Park |█████████████████████████████████████████ | 32.9°C — Wales May record
Jersey |████████████████████████████████████████████ | 34.2°C — Channel Islands record
Guernsey |████████████████████████████████████████ | 31.5°C — Guernsey record
Previous UK May record|███████████████████████████████████ | 32.8°C (1922) — beaten by 2.3°C
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Tropical night (26 May): 21.4°C minimum at Camborne, Cornwall — UK May minimum record
Source: Met Office; Wikipedia May 2026 UK Heatwave
| May 2026 Record | Temperature | Location / Detail |
|---|---|---|
| UK hottest May day (final) | 35.1°C | Kew Gardens, London, 26 May 2026 |
| UK hottest May day (provisional first record) | 34.8°C | Kew Gardens, London, 25 May 2026 |
| Previous UK May record (1922) | 32.8°C | Broken by 2.3°C — a full 2°C margin |
| Wales May temperature record | 32.9°C | Bute Park, Cardiff |
| Jersey May record | 34.2°C | Channel Islands |
| Guernsey May record | 31.5°C | Channel Islands |
| Highest minimum May temperature (tropical night) | 21.4°C | Camborne, Cornwall, 26 May |
| Heatwave threshold reached | 24 May 2026 | Eight locations in Essex, London, Oxfordshire, Suffolk |
| First UKHSA yellow alert issued | 22 May 2026 | East Midlands, East of England, London, South East, West Midlands |
| Peak alert level reached (May) | Amber | England-wide by 24 May |
Source: Met Office press releases May 25 and 26, 2026 (metoffice.gov.uk); Wikipedia — May 2026 United Kingdom Heatwave; House of Commons Library, updated June 2026
A climate attribution study published the previous summer by Met Office scientists found that the chances of surpassing the May temperature record have been increasing as the climate changes as a consequence of human greenhouse gas emissions. The study found that breaking the 32.8°C May record is around three times more likely now in our current climate than it would have been in a natural climate not impacted by greenhouse gas emissions — what was around a 1-in-100 year event is now around a 1-in-33 year event.
The Kew Gardens recording of 35.1°C on 26 May was the culmination of a four-day heat build from 22 May that saw progressively broken records. The margin of the May record breach — 2.3°C — is exceptionally large for a temperature record. Long-standing records in weather science are rarely exceeded by more than a fraction of a degree; a 2.3°C margin indicates the climate system is not nudging gradually past old baselines but jumping through them. University of Reading climate scientists described the event as “an intense and record-breaking spell of heat,” adding that “long-standing records are being shattered, potentially by a significant margin, and with temperatures edging dangerously close to levels previously thought almost unimaginable in the UK.”
June 2026 UK Heatwave Temperature Forecast and Records
June 2026 Heatwave Temperature Forecast (Met Office, June 24, 2026)
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Thursday 25 Jun peak |████████████████████████████████████████████████| 38°C (southern England)
Wednesday 24 Jun peak |████████████████████████████████████████████ | 37°C–38°C (Reading ~40°C possible)
Tuesday 24 Jun |█████████████████████████████████████████████ | 37°C (southern England)
Friday 26 Jun |████████████████████████████████████ | 33°C (eastern areas)
Wales overnight min |████████████████████████████████████████████████| 20.3°C at St Athan (June record)
Current UK June record|█████████████████████████████████ | 35.6°C (1957/1976)
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Dew point Wednesday–Thursday: ~22°C (vs single figures in July 2022)
Source: Met Office Red Warning June 24, 2026; University of Reading June 24, 2026
| June 2026 Metric | Data |
|---|---|
| Peak temperature forecast | 38°C (Thursday 25 June, southern England) |
| Met Office peak forecast day | Thursday 25 June |
| Reading temperature forecast (24 June) | Up to 40°C — University of Reading |
| Temperature exceeding 30°C | Widespread across England and Wales Wed–Thu |
| Dew point forecast (Wed–Thu) | ~22°C — exceptional for UK |
| Tropical nights forecast | Widespread — minimum above 20°C across England and Wales |
| Wales overnight minimum record (23 June) | 20.3°C — St Athan, South Glamorgan |
| Amber warnings additionally issued | Friday and Saturday, shifting east |
| Current UK June record | 35.6°C (28 June 1976; 29 June 1957) |
| Met Office assessment of record risk | “Very likely to be exceeded” |
| Heat dome mechanism | High pressure parked over UK/western Europe |
| Jet stream behaviour | Split into two branches, suppressing Atlantic weather systems |
Source: Met Office Red Extreme Heat Warning, June 22, 2026 (metoffice.gov.uk); Met Office Red Warning updated June 24, 2026; University of Reading expert comment, June 24, 2026 (reading.ac.uk)
The driving force is a heat dome — a high pressure system parked over the UK and western Europe, suppressing cloud formation and allowing relentless sunshine to bake the ground. Air sinking beneath the high pressure compresses and warms, like air heating inside a bicycle pump. The June 2026 humidity profile is historically unprecedented for Britain. Even the 2003 European heatwave — which killed over 70,000 across Europe — was primarily a dry heat event in the UK. A wet bulb temperature combining 38°C air temperature with 22°C dew points produces heat stress comparable to tropical climates, in a country with minimal air conditioning in homes, hospitals, schools, or public transport.
UK Heatwave Health Impacts and Excess Deaths 2022–2026
UK Excess Heat Deaths by Year — England and Wales (UKHSA/ONS)
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2017 |████ | 778
2018 |████████ | 863
2019 |████████ | 892
2020 |████████████████████████ | 2,244
2021 |████████████████████ | 1,634
2022 |████████████████████████████████████████████| 2,803 (record — 65+ age group)
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Peak day rate July 2022: 253 excess deaths per day (17–20 July, 65+)
Source: ONS/UKHSA Excess Mortality During Heat-Periods, 2022 (ons.gov.uk)
| Health and Mortality Metric | Data |
|---|---|
| Total excess deaths (65+) during 2022 summer heat-periods | 2,803 — highest since Heatwave Plan introduced 2004 |
| Previous highest (2006) | 2,323 |
| Peak excess deaths — July 2022 (17–20 July, 4 days) | 1,012 (253 per day) |
| Highest single heat-period deaths — 2022 | 1,458 (August 8–17, 10 days) |
| Water-related deaths — May 2026 heatwave | At least 15 (9 children) |
| UKHSA Heat-Health Alert levels | Yellow, Amber, Red (active June 24, 2026) |
| Red alert activation (Level 4) | Illness and death expected among fit and healthy |
| Age group highest risk | 65 and over; also babies, outdoor workers, those with cardiovascular/respiratory conditions |
| 2022 wildfires across UK | ~25,000 |
| 2022 drought declared | August — many regions across England |
| 2022 excess deaths — all ages (not just 65+) | Close to 3,000 (UKHSA estimate) |
Source: ONS/UKHSA — Excess Mortality During Heat-Periods, England and Wales, 1 June to 31 August 2022 (ons.gov.uk); Wikipedia — 2022 United Kingdom Heatwaves; House of Commons Library Heatwaves in the UK; UKHSA Heat Health Alert System documentation
Across the five heat-periods of 2022, estimated excess mortality in those aged 65 years and over totalled 2,803 — the highest since the Heatwave Plan was introduced in 2004. During the peak (17–20 July), 1,012 excess deaths occurred over four days — 253 per day.
The 2026 June heatwave’s humidity makes its health profile more dangerous than 2022’s dry heat. Humidity prevents sweat evaporation, so core body temperature rises faster and with less warning. The UKHSA Red alert reflects extreme temperature, high humidity, tropical nights, and June timing — when bodies have not yet acclimatised to summer heat. The Red level exists because June 2026 conditions are dangerous for the general population, not only high-risk subgroups.
UK Heatwave Infrastructure Impacts in 2026
Infrastructure Disruptions — May 2026 and June 2026 Forecast
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Rail (May 2026) |████████████████████████████████████████| Multiple lines — speed restrictions, signalling failures
Water supply (May 2026) |████████████████████████████████████ | ~18,000 properties (Kent peak)
Road (June 24, 2026) |████████████████████████████████████████| RAC +10% breakdowns above normal
Power and energy |████████████████████████████████████ | Demand surge + risk of supply issues
Schools |████████████████████████████████ | Closures/PE kit exemptions during peak heat
Water safety |████████████████████████████████████████| Beaches, lakes, rivers — increased incidents
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Source: Wikipedia May 2026 UK Heatwave; RAC June 24, 2026; Met Office June 2026
| Infrastructure Sector | Impact | Data |
|---|---|---|
| Rail (South Western Railway — May) | Speed restrictions, signalling faults, track defects | All lines affected 26 May 2026 |
| Rail (Peterborough-Stevenage-Kings Cross — May) | Heat-related disruption | Services disrupted |
| Rail (Avanti West Coast — May) | Points/signalling failures at London Euston | Milton Keynes–Watford Junction blocked |
| London Underground (May) | Multiple line disruptions | Speed restrictions |
| Water supply — Kent (May peak) | ~18,000 properties | Ashford, Maidstone, Whitstable |
| Water supply — Eastbourne | 168 properties affected | Failed pump |
| Road (June 24, 2026) | +10% RAC breakdowns above normal Tuesday rate | Overheating vehicles |
| Power and water (June forecast) | Authorities warned of potential supply risks | Met Office/Government |
| Schools (2022 and forecast 2026) | Closures or uniform exemptions on hottest days | National pattern |
| Coastal water safety (June 2026) | Increased incident risk | RNLI + RLSS warnings issued |
Source: Wikipedia — May 2026 United Kingdom Heatwave; RAC Drive UK Heatwaves update June 24, 2026; Met Office June 22 and June 24, 2026 press releases; RNLI/RLSS public safety warnings
Rail transport was severely disrupted during the May 2026 heatwave, with South Western Railway saying all lines were being affected by heat-related speed restrictions, multiple signalling faults, and track defects. Heat-related incidents between Peterborough and Stevenage disrupted services on some lines. Avanti West Coast services were hit by points and signalling failures at London Euston, whilst high track temperatures led to speed restrictions on multiple routes.
RAC patrols were recording +10% breakdowns above normal on Tuesday 24 June, with demand expected to grow further as temperatures peaked. Rail infrastructure is designed for a temperate climate: steel rails can buckle at approximately 46°C rail temperature — achievable when air temperatures exceed 30°C in direct sunshine. Speed restrictions prevent derailment but cascade delays across already capacity-constrained networks.
UK Heatwave Climate Change Context in 2026
UK Temperature Trend — How Extremes Have Changed (Met Office / Commons Library)
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1976 summer |████████████████████████████ | Exceptional dry heatwave — benchmark for decades
2003 summer |████████████████████████████████ | 38.5°C UK record at the time
2019 summer |██████████████████████████████████████ | 38.7°C — new record (Cambridge)
2022 summer |████████████████████████████████████████████| 40.3°C — UK all-time record (Coningsby)
2025 spring |████████████████████████████████████████████| Warmest/sunniest spring on record; 4 summer heatwaves
2026 spring |████████████████████████████████████████████| New May record 35.1°C; June Red warning
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Climate change has made extreme UK heat ~10x more likely (Met Office)
Chance of 40°C recurrence: 50/50 within 12 years (Wiley/RMetS 2025 study)
Source: Met Office; House of Commons Library; RMetS Weather Journal 2025
| Climate Context Metric | Data |
|---|---|
| UK all-time temperature record | 40.3°C — Coningsby, Lincolnshire, 19 July 2022 |
| Stations exceeding previous UK record on 19 July 2022 | More than 40 |
| Scotland all-time record (set July 2022) | 34.8°C — Charterhall |
| Climate change effect on extreme UK heat probability | ~10x more likely (Met Office) |
| Without climate change — 40°C UK probability | “Extremely unlikely” — Met Office attribution |
| Return period of 40°C event in 2023 climate | 1-in-24 years (RMetS study, June 2025) |
| 50/50 chance of another 40°C by | Within 12 years — RMetS/Wiley 2025 study |
| Probability of May record before current climate | 1-in-100 years; now 1-in-33 (Met Office) |
| Summer 2022 — UK mean temperature | 17.1°C (joint hottest summer on record) |
| 2022 — first year UK annual average exceeded 10°C | UK’s warmest year since records began 1884 |
| Heatwaves by 2050 projection | More frequent and intense — Met Office / Commons Library |
| 2026 Summer 2026 forecast | Potentially several more heatwaves before end of August |
Source: Met Office — How Has Summer Warmth Changed in the UK? (metoffice.gov.uk, June 2026); House of Commons Library — Heatwaves in the UK (June 2026); Wikipedia — 2022 United Kingdom Heatwaves; Royal Meteorological Society / Wiley — Rapidly Increasing Chance of Record UK Summer Temperatures (June 2025); Met Office climate attribution studies
On 19 July 2022, the UK recorded 40.3°C for the first time at Coningsby, Lincolnshire — a threshold once considered highly unlikely. More than 40 stations exceeded the previous UK record of 38.7°C on that single day. According to the Met Office, extreme heat has been made ten times more likely by climate change in the UK, with attribution studies confirming “without human-caused climate change, temperatures of 40°C would have been extremely unlikely.” A peer-reviewed study published in the Royal Meteorological Society’s journal estimated the 2023 return period of a 40°C event at 1-in-24 years, with a 50/50 chance of recurrence within 12 years. The trajectory from 1976 through 2003, 2019, 2022, 2025, and now 2026 is not random — it is a systematic shift in the distribution of summer temperatures. The 2026 summer season, having already delivered a record-breaking May heatwave and a Red-warning June event, is tracking toward what climate scientists are now treating as the new baseline for British summers.
Disclaimer: The data research report we present here is based on information found from various sources. We are not liable for any financial loss, errors, or damages of any kind that may result from the use of the information herein. We acknowledge that though we try to report accurately, we cannot verify the absolute facts of everything that has been represented.
