Met Office Names 50 Areas Facing 40C Heatwave on Wednesday – Full List

The Met Office has issued an extremely rare red warning for extreme heat across 50 local authority areas in England and Wales, with temperatures forecast to reach up to 40C on Wednesday and Thursday.

Brit Brief 22/06/2026 10:23

Met Office Names 50 Areas Facing 40C Heatwave on Wednesday – Full List — Met Office Lists 50 Areas Under Rare Red Heat Warning

The Met Office has issued an “extremely rare red warning” for extreme heat, forecasting temperatures of up to 40°C across parts of England and Wales this week. The warning covers 50 local authority areas and comes into force at 9am on Wednesday, June 24, remaining active until 9pm on Thursday, June 25. Forecasters warn of serious illness and potential danger to life, with widespread impacts expected for the general population.

Warning Details and Timing

In an update issued on Monday morning, the Met Office stated: “During the heatwave expected to affect a large part of England and Wales this week, the highlighted area now looks increasingly likely to see a two to three day period where maximum temperatures in the shade exceed 37 Celsius, perhaps rising to 38 to 40 Celsius in some places. The heat will be accompanied by high humidity, exacerbating the potential for discomfort and health impacts, with very warm and humid night times also reducing the ability for people to recover overnight.”

Impacts on Health and Infrastructure

The red warning indicates that “population-wide adverse health effects” are likely, potentially leading to “serious illness or danger to life.” It also highlights risks of transport disruption, including delays and cancellations on rail and air networks, increased pressure on power and water supplies, and a greater risk of incidents around rivers, lakes, and coastal areas. The Met Office added: “Significant disruption to daily life is likely and the public should take every effort to make precautions and adapt their daily routines where possible to cope with these levels of heat, which up to now have been extremely rare for the UK.”

—

Wide Pickt banner — collaborative shopping lists app for Telegram, phone mockup with grocery list

Public Health Advice

Britons have been urged to stay hydrated, avoid strenuous activity during the hottest part of the day, and check on elderly or vulnerable relatives and neighbours. The Met Office’s warning is accompanied by a map highlighting the affected regions, which stretch from the East Midlands down to South West England and across much of Wales.