The Met Office has issued a rare red weather warning for extreme heat, covering 36 counties across Wales and England, with temperatures expected to surge to 37°C in London and 35°C in Cardiff. The warning, in force from 9am Wednesday to 9pm Thursday, advises people to avoid going outside between 11am and 3pm when the sun is strongest.
Affected Areas
The red warning spans from Swansea in west Wales to Monmouthshire in the east, including Cardiff and the Valleys. In England, it covers much of the Midlands, London, the south-west and south-east. Among the worst-affected areas are London, forecast to reach 37°C on Wednesday, and Cardiff, expected to hit 35°C.
Met Office Guidance
The Met Office stated: "An exceptional spell of hot and humid weather is expected across this region, with impacts to the general population highly likely." Their foremost advice is to "keep out of the sun and avoid any exercise between 11am-3pm when the sun is strongest."
Further recommendations include:
- Close curtains in rooms that face the sun
- If going out, take water, stay in shade, wear sunscreen and a wide-brimmed hat
- When entering water (sea, river, lake), enter gradually to avoid cold-water shock; go to lifeguarded beaches
- Check travel conditions; if using public transport, take water and a handheld fan, dress in light fabrics, and watch for fellow passengers struggling
Temperature Timeline
Cardiff is forecast to reach 30°C on Monday, London 36°C on Tuesday. Despite the warning expiring Thursday, London is still expected to record 32°C on Friday. Several train services, including London Paddington to Reading and routes in south Wales, are experiencing delays or cancellations due to the heat.
What Is a Red Weather Warning?
A red warning is the Met Office's most serious alert, indicating hazardous weather with significant risk to life and potential failure of critical infrastructure such as power cuts or road/rail closures. The public is advised to avoid unnecessary journeys and follow emergency services' guidance. The three warning levels are: yellow (potential impact, take precautions), amber (likely widespread impact, protect yourself and property), and red (severe impact, immediate action to stay safe).
Will Schools Close?
The UK government advises that schools should not normally close during hot weather, as attendance is paramount. However, school leaders should ensure children's safety and comfort, possibly relaxing uniform rules and limiting physical activity.
Full List of Affected Counties
Northamptonshire, Bedfordshire, Cambridgeshire, Essex, Hertfordshire, Buckinghamshire, Sussex, Greater London, Hampshire, Kent, Oxfordshire, Surrey, Berkshire, Somerset, Bristol, Dorset, Gloucestershire, Wiltshire, Blaenau Gwent, Bridgend, Caerphilly, Cardiff, Carmarthenshire, Merthyr Tydfil, Monmouthshire, Neath Port Talbot, Newport, Powys, Rhondda Cynon Taf, Swansea, Torfaen, Vale of Glamorgan, Herefordshire, Warwickshire, West Midlands Conurbation, Worcestershire.
