Met Office issues rare red weather warning for 38C heatwave

The Met Office has issued a rare red extreme-heat warning for parts of central and southern England and Wales as the UK braces for an intense midweek heatwave.

Forecasts point to temperatures of around 38C, with some reports saying the hottest places could reach 39C or even 40C. The red warning is the most serious in the Met Office system and signals conditions that can pose a risk to life.

The warning period cited in reporting runs from 9am on Wednesday, June 24, 2026, to 9pm on Thursday, June 25, 2026.

What forecasters say the heat could do

The Met Office says the heat will require substantial changes to working practices and daily routines. Official language quoted in coverage says the whole population is at risk, not only older people or other vulnerable groups.

The agency has also warned of disruption to transport, energy, water and mobile services. Very warm, humid nights are expected to limit recovery between the hottest periods of the day.

That lack of overnight relief is part of what makes the event unusually severe. It increases the chance that people, buildings and infrastructure remain under stress for longer.

Where the warning applies

Coverage of the exact footprint varies slightly, but reporting is consistent that the red zone covers parts of central and southern England and reaches into Wales.

Several reports say this is only the second red heat warning the Met Office has ever issued. It is also the first to include Wales.

The geographic spread matters because the warning is not limited to a single city or county. It stretches across a broad area where schools, workplaces, transport operators and local authorities may all be affected at once.

How the alert escalated

The heatwave had already been building before the red warning was issued. On Sunday, June 21, 2026, reporting based on Met Office forecasts said temperatures could reach record-breaking levels, with highs of 38C and a chance of 40C in some places.

By Tuesday morning, June 22, The Times reported that a rare red warning had been issued for central and southern England and Wales.

Later on June 22, the Financial Times also reported the red warning and said temperatures could reach at least 39C. The Guardian then reported the warning again, along with the UK Health Security Agency’s red heat health alert for six English regions.

Health risk and official warnings

The UKHSA red alert underlines the public-health risk as the hottest days approach. Reporting says the alert applies to six English regions and is meant to signal the potential for serious health impacts.

The Met Office has stressed that the danger is not limited to a narrow group of vulnerable people. Officials are warning that prolonged heat can affect anyone, especially people working outdoors, travelling, or spending long periods in buildings that retain heat.

Very warm nights are a particular concern because they reduce the body’s chance to recover. In a multi-day heat event, that can make the impact worse even if the daytime peak is brief.

Disruption already starting

The forecast is already changing plans. Schools and sports fixtures have begun adjusting schedules, with UK media reporting early closures and cancellations in response to the heat.

Transport operators, local authorities and event organisers are now facing the prospect of further disruption once the warning period begins in earnest.

Road, rail and air services are among the sectors being watched most closely, alongside the possibility of strain on power, water and mobile networks if demand rises during the hottest hours.

What happens next

The main open question is whether the hottest spots stop at 38C or climb into the 39C to 40C range.

Another is whether the Met Office or UKHSA will expand, narrow or extend the warnings as the heatwave develops.

The practical test comes on Wednesday and Thursday, when the red warning takes effect and schools, workplaces, transport systems and essential services are pushed to cope with extreme heat across parts of England and Wales.