UK June temperature record broken anew as France delays Pride and Poland issues wildfire warning

Britain sweltered through its hottest June day on record for the third time this week on Friday, with the mercury hitting 36.9C in Wattisham, Suffolk – a temperature that fell outside the area covered by the Met Office’s red extreme heat alert. The Met Office confirmed the provisional reading and said temperatures were still rising. The previous records of 36.7C in Merryfield, Somerset, and 36.1C in Gosport, Hampshire, were set on Thursday and Wednesday respectively. Wales also recorded its hottest June day provisionally, with 35.9C in Cardiff, while night‑time temperature records for the month were broken at 23.5C in Cardiff and 23.0C in Plymouth.

Ozone pollution breaches safety levels

The extreme heat has also driven ozone air pollution across the UK above World Health Organization safety levels at most government monitoring sites, according to Dr James Weber, a researcher at the University of Reading. “This week ozone breached World Health Organization safety levels at most [government] air pollution monitoring sites,” he said. “On Tuesday, 60 of the 97 sites measuring ozone went over the limit; 55 did so on Wednesday and 54 on Thursday, primarily in southern England. Levels are likely to stay high throughout the heatwave.” Ozone, which is produced more readily in high temperatures and strong sunlight, is harmful to breathe – particularly for older people, children and those who are medically vulnerable – and can worsen the health impacts of the heat itself, Dr Weber added.

Hospitals and ambulance services overwhelmed

Health chiefs have warned of a sharp rise in life‑threatening emergencies. The London Ambulance Service (LAS) responded to its highest number of such calls ever on Wednesday, a 50% increase compared with a typical Wednesday, while cardiac arrests rose by 30%. Craig Harman, the LAS chief operating officer, said he expected “demand to grow day on day over the next couple of days”. He urged people to drink “plenty of water” even when not thirsty, to stay out of the sun during the hottest hours and to avoid exercising outside. The service has deployed more than 400 extra ambulance crews to cope. Several hospitals have declared critical incidents, and University Hospital Southampton cancelled planned operations and outpatient appointments. The Royal College of Physicians highlighted how the heat exposes infrastructure weaknesses in the NHS, with reports of elderly care wards exceeding 30C. Schools and nurseries have been forced to close, and a hosepipe ban has been introduced in Kent because of surging demand.

Energy system strained as heat disrupts generation

Great Britain’s energy system operator, the National Energy System Operator (Neso), has issued a second market warning this week, asking generators to provide extra electricity on Friday evening to meet rising demand from air conditioners and electric fans. Neso said its forecasts showed “tight margins on the electricity system” because of “the impact of extremely high temperatures affecting Great Britain and the continent”. The government‑owned body stressed that the electricity supply was not at risk and that a blackout was not imminent, but it has been forced to pay prices well above the usual market rate for extra power, costs that will ultimately be passed on to household energy bills. The heat has also affected generation: some gas power plants in the UK have cut output, and French nuclear reactors have suffered outages because river water used for cooling has become too warm.

Europe scorches from the Balkans to the Baltic

The heatwave that has already shattered records in France – where temperatures reached 43.8C on Wednesday, the hottest day ever recorded – is now spreading eastward. Poland and Germany are braced for highs of up to 40C this weekend, with Poland also warning of increased wildfire risk after record‑low May rainfall. Several Polish cities have installed water curtains to help pedestrians cool down. Poland’s long‑distance rail operator, PKP Intercity, warned that overhead power lines could sag and rails deform, and said passengers could cancel this weekend’s journeys for a full refund – following the example of Germany’s Deutsche Bahn.

In the Balkans, temperatures of up to 39C are forecast in parts of Serbia, Bosnia, Croatia, Kosovo, North Macedonia and Montenegro, prompting health warnings, especially for vulnerable groups. Most of the Adriatic coast is under red warnings, with temperatures expected to top 35C. In Serbia, where the past three summers have been the hottest since records began in 1951, more than one in five workers works outdoors.

Italy now has 18 cities under red heat alerts, including Genoa, Bologna, Florence, Rome, Turin and Verona. The Uffizi Gallery in Florence has restricted entry to pre‑booked ticket holders only, citing malfunctioning air conditioning, while Palermo’s courthouse suspended hearings until 29 June. Clam fishers working near the Po River estuary reported that algae blooms spawned by the heat are killing large numbers of clams. “On top of all our problems, now there’s this crazy heat, so long, so unexpected,” said Paolo Mancin, head of a fishers’ cooperative.

Belgium, where temperatures are approaching June records, cancelled the annual re‑enactment of the Battle of Waterloo this weekend. Organisers said safety could not be compromised. In France the Paris Pride March and the Solidays music festival were postponed, and the country’s drought has raised wildfire warnings. Spain has also seen new June temperature records, with some locations exceeding 40C and even 45C, and wildfires disrupting high‑speed rail services.

Datacentres and the urban heat island effect

Residents living next to Europe’s largest datacentre park, in Slough, say the heat has become unbearable. Nabeel Nawaz, a local store manager, described the sensation as “pinching your body and burning your skin”. Slough hosts an estimated 30 to 40 huge datacentres, owned by companies such as Equinix and Digital Realty and serving clients including Amazon, Google, Oracle and Microsoft. More are planned. Emerging research, including a preprint of a paper led by Cambridge University, suggests that datacentres create a heat‑island effect, raising local temperatures by an average of 2C and by as much as 9C in their immediate vicinity.

Government launches climate security taskforce

In response to the growing threats posed by climate change, the UK government has launched a new taskforce of leading security, military and academic experts. Co‑chaired by climate minister Katie White and security minister Dame Angela Eagle, the group will advise the government on how to better anticipate and respond to climate‑related risks to national security, including geopolitical instability and economic disruption. Officials said the taskforce would meet to pinpoint gaps in the UK’s preparedness and set out clear recommendations to strengthen resilience.

Science behind the heatwave

Meteorologists attribute the heatwave to a powerful “heat dome” stretching across Western and Central Europe, which traps hot air from North Africa and prevents cooler Atlantic systems from providing relief. Scientists are also using wet‑bulb globe temperatures to assess the additional danger of high humidity, which makes sweating less effective at cooling the body. The current heatwave is unequivocally a marker of human‑induced climate change, climatologists have shown. As recently as 2003 a heatwave of this magnitude would have been about 2C cooler, and in 1976 it would have been 3.5C cooler, because of lower global heating levels. Night‑time temperatures today are roughly 100 times more likely than they were in 2003.

F1 heat hazard and other impacts

The Austrian Grand Prix, taking place this weekend in Spielberg, has declared a heat hazard – the first race this season to do so. Temperatures are expected to climb into the low 30s Celsius during the race, almost 10C above the venue’s norm. Under new FIA regulations, teams must equip cars with advanced driver cooling systems to cope.