UK Met Office issues rare red weather warning for Wednesday and Thursday

What the Met Office said

The Met Office has issued a rare red weather warning for extreme heat covering parts of England and Wales on Wednesday and Thursday, warning of a genuine risk to life as temperatures rise.

Forecasters said some areas could see maximum temperatures in the shade exceed 37C, with the hottest places potentially reaching 38C to 40C. They also warned that very high humidity and unusually warm nights will limit overnight recovery.

The warning covers southern Wales and parts of southern and central England, including London and areas stretching from Kent and Sussex to Somerset, Birmingham and southern Cambridgeshire.

Why the alert matters

A red warning is the Met Office's highest weather alert level and is reserved for conditions with a high likelihood of serious impacts. In this case, officials said the heat could pose a genuine risk to life.

The warning comes with concerns about serious illness, especially for older people, young children and others who are more vulnerable to extreme heat. The Met Office said the conditions could also strain health services.

It is only the second red heat warning ever issued in the UK, and the first to include Wales.

Likely disruption

The Met Office warned that the heat could disrupt rail, road and air travel, along with heat-sensitive systems and equipment.

It also said the event could affect power, water, gas and mobile services, raising the possibility of outages or other failures if infrastructure is pushed to its limits.

Transport operators, utilities providers and emergency services are all likely to be watching the warning closely as temperatures build through the week.

What people are being told to do

The Met Office advised people to take precautions, including staying hydrated and avoiding strenuous activity during the hottest part of the day.

Officials are also warning people to plan ahead if they need to travel or work outdoors, because the red alert signals a level of disruption that could affect daily life across the warning area.

The wider context

The warning follows several days of heat alerts and comes as part of a broader European heatwave affecting multiple countries.

The key question now is whether the Met Office extends the warning beyond Thursday and how close temperatures get to the forecast upper range in the hottest areas.

Officials and services across the warning zone are likely to keep updating advice as the heat event develops.