More than 1,000 schools across England and Wales have been forced to close fully or partially as Britain experiences one of its most intense heatwaves in recent years.
The widespread disruption comes as a rare red warning for extreme heat has been issued by the Met Office, covering London, the South East, parts of the South West, the Midlands and south Wales.
The warning, the highest level available, remains in force until 9pm on Thursday and warns of possible risks to life.
Across Wales, more than 500 schools have either closed or shortened their opening hours because of the soaring temperatures. Closures have affected schools in areas including Blaenau Gwent, Caerphilly, Bridgend, Cardiff, Carmarthenshire, Merthyr Tydfil, Monmouthshire, Neath Port Talbot, Newport, Powys, Rhondda Cynon Taf, Swansea, Torfaen and the Vale of Glamorgan.
In England, at least 578 schools are known to have shut completely or partially, with the majority located in southern parts of the country. The true figure is expected to be significantly higher, as many councils do not publish comprehensive closure lists and some schools operate independently through academy trusts.
The closures have largely come after the end of the main GCSE, A-level and other examination periods, reducing the impact on students sitting public exams.
Forecasters are warning that temperatures are likely to climb even higher than those seen earlier this week. Tuesday’s highest temperature was 34.6C at Wisley in Surrey, but conditions on Wednesday are expected to be hotter still.
Temperatures of 37C or 38C are forecast in parts of southern England, while a peak of 39C has not been ruled out. If those figures are reached, the current UK June temperature record of 35.6C is likely to be broken.
Large areas of south-west England, east Wales, the Midlands and northern England are expected to experience temperatures between 30C and 34C, with high humidity making conditions feel even more uncomfortable.
The Met Office says the red warning represents an “exceptional spell” of hot and humid weather and is only the second time such an alert has been issued for extreme heat since the warning system was introduced in 2021.
Unlike yellow or amber warnings, a red warning is reserved for weather conditions expected to have severe and widespread impacts. The Met Office has warned that the heat could affect the entire population, not only those who are traditionally considered vulnerable.
Officials say serious illness and danger to life are possible, while heat-sensitive infrastructure could also be affected. There are concerns that power supplies, water services, telecommunications and transport networks could come under strain during the hottest period.
Rail passengers have been advised to avoid non-essential travel where possible, while motorists have been warned to expect delays. The Met Office says road closures, rail disruption and flight delays are all possible as infrastructure copes with the extreme temperatures.
The heatwave is also prompting safety warnings around open water, with authorities concerned that more people will seek relief from the heat at beaches, rivers, lakes and reservoirs.
Animal welfare organisations have urged pet owners to take extra precautions. The RSPCA has advised dog owners to avoid walking their pets during the hottest part of the day and, in areas covered by the red warning, to consider avoiding walks altogether until temperatures fall.
People are being urged to drink plenty of water, wear loose-fitting clothing, stay in the shade where possible and check on elderly relatives, neighbours and others who may be at greater risk from the extreme conditions.
While England and Wales face the most severe heat, Scotland and Northern Ireland are expected to remain cooler, with temperatures generally reaching the low to mid-20s.
