Extreme heat is sweeping across the UK, bringing closures, disruption, and a rare red weather warning.
Temperatures are expected to reach 40C in parts of England and Wales on Wednesday and Thursday, as a “heat dome” settles over western Europe.
The Met Office has issued a red extreme heat warning covering a swathe of the country.
How hot will it get today?
This warning, in place from 9am on Wednesday to 9pm on Thursday, stretches from London to Swansea and Somerset up to Birmingham.
The heatwave could come close to the UK’s all-time temperature record of 40.3C, set in Lincolnshire in July 2022.
The highest June temperature on record is 35.6C, recorded in Hampshire in 1976.
Grahame Madge, a spokesman for the Met Office, said: "The Met Office is flagging 39C as a headline maximum temperature on Thursday, most likely for somewhere in London or the South East.
"It is possible we could see temperatures higher than the 39C if the final values are at the upper end of our narrow range."
He added that the high humidity will worsen the impact of the heat, making it even more difficult for people to cope.
⚠️⚠️🔴 Red weather warning issued 🔴⚠️⚠️
Extreme heat across parts of central/southern England and Wales
Wednesday 0900 - Thursday 2100
Latest info 👉 https://t.co/QwDLMfRBfs
Stay #WeatherAware ⚠️ pic.twitter.com/IwXnyU1E7y— Met Office (@metoffice) June 22, 2026
London is expected to be among the hottest areas.
On Tuesday, the highest temperature recorded was 34.6C in Wisley, Surrey.
What are the risks of the red weather warning?
The red warning brings with it serious health and safety risks.
The Met Office has warned of potential impacts to public health, infrastructure, water and power supplies.
A spike in water safety incidents is also expected, as more people head to rivers, lakes and the coast to cool off.
These alerts indicate that the heat poses a significant risk to the wider population, not just vulnerable groups.
What areas are covered by heat warnings?
The UK Health Security Agency (UKHSA) has also issued red heat health alerts for the East of England, East Midlands, London, the South East, the South West and the West Midlands.
Amber alerts are in place for the North East, North West, and Yorkshire and the Humber.
What disruption can you expect from the heatwave?
The heat is already causing widespread disruption.
Nearly 100 schools in Somerset and a similar number in Buckinghamshire will close fully or partially on Wednesday and Thursday.
Parents in Gloucestershire will also be affected, with 86 schools closing.
Some schools are allowing children to wear PE kits instead of full uniforms.
Transport is also affected as the National Rail has warned of delays and cancellations on Gatwick Express, Great Northern, Southern, and Thameslink services.
Eurostar has cancelled four trains between London and Paris, and Avanti West Coast will run reduced services between Tuesday and Thursday.
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Chiltern Railways has cancelled more than half of its services until Friday.
The London Fire Brigade has urged people to be cautious and avoid using disposable barbecues in parks or open spaces.
NHS trusts, including Moorfields Eye Hospital and Barts Health NHS Trust, have advised patients to bring water and check travel arrangements.
The NHS has advised people to stay out of the heat when possible, eat cold foods, stay hydrated, and keep windows closed during the hottest part of the day.
Authorities across the UK will continue to monitor the situation as extreme heat brings further risks and disruption.
How are you coping in the hot weather? Let us know in the comments.
