Red and amber heat warnings have been issued across large areas of the UK, with the Met Office warning of risks to life, major disruption and possible failures to essential services. The alerts cover parts of England and Wales from Wednesday into Thursday, as forecasters warn that exceptionally high temperatures and humidity could place pressure on public health, infrastructure and energy networks.
The Met Office has upgraded its warning level for dozens of local authority areas, issuing a red extreme heat warning from 9am on Wednesday until 9pm on Thursday. The warning applies to locations including Greater London, parts of the Midlands, the South West and South Wales.
According to the Met Office, the expected conditions are developing into what it described as an “impactful severe weather event”, with the potential for record-breaking June temperatures and prolonged overnight warmth.
Red Warning Highlights Risks to Health, Travel and Essential Services
The red warning represents the highest level of weather alert issued by the Met Office. The agency said the forecast heat poses a risk to life across the wider population and is not limited to people normally considered vulnerable to extreme temperatures.
According to Met Office deputy chief forecaster Tom Crabtree, the combination of heat and humidity is expected to be “oppressive” and could affect many aspects of daily life. He said impacts could extend from public health and transport systems to power and water supplies.
The Met Office also warned that significant disruption to travel is likely during the warning period. Energy supplies and communications infrastructure could be affected, with potential interruptions to water, electricity, gas and mobile phone services.
Another concern is the persistence of high overnight temperatures. Crabtree noted that several consecutive nights may remain above 20C, a condition known as a tropical night. According to the Met Office, these warm nights can make it difficult for people to recover from daytime heat, increasing heat-related stress.
The red warning covers areas including Bedford, Cambridgeshire, Essex, Hertfordshire, Greater London, Hampshire, Kent, Oxfordshire, Surrey, Bristol, Somerset, Cardiff, Swansea, Herefordshire, Warwickshire and the West Midlands conurbation, among others.
Households Advised to Prepare for Possible Power Outages
Alongside the health warnings, the Met Office has advised households to prepare for the possibility of power cuts during the heatwave. According to its guidance, heat-sensitive systems and equipment could fail under the forecast conditions, leading to losses of power and other services.
The agency said substantial changes to working practices and daily routines may be required in affected areas. It warned that failures involving essential infrastructure are considered likely during the period of extreme heat.
The Met Office has urged people to take practical precautions. Its advice includes drinking plenty of fluids, avoiding strenuous exercise during the hottest part of the day, staying in the shade, closing curtains in sun-facing rooms and carrying water when travelling outdoors.
According to the Met Office’s guidance on power outages, households should also ensure mobile phones remain fully charged so they can be used in an emergency. The agency recommends gathering items such as torches, spare batteries and mobile phone power packs in advance.
For people who depend on electrically powered medical equipment, the Met Office advises contacting their local distribution network operator, which may be able to provide assistance through a priority support register during any disruption to electricity supplies. Amber heat warnings remain in force across a wider area of England and Wales, covering additional locations in the North of England, the South West and Wales through Thursday.
