Japan records its first ‘cruelly hot day’ as cities swelter in 40-degree heat

Japan’s meteorological agency coined the term kokushobi – or “cruelly hot day” to warn the public of dangers tied to extreme heat. Photograph: Nicolas Datiche/SIPA/Shutterstock

by  Gavin Blair in Tokyo

 In April Japan coined new term kokushobi for days above 40C as country advises workers to wear shorts to the office to cope with stifling heat

 

Japan logged its first official kokushobi or “cruelly hot day” on Tuesday since the new term for when temperatures top 40 degrees Celsius was introduced in April. The Japan Meteorological Agency coined the new designation to warn the public of the heat dangers of days that were once freak weather events but have now become more common.

The central Japan cities of Gujo and Tajimi in Gifu prefecture, along with Toyota in Aichi prefecture, all hit 40C. Gujo’s 40C and Toyota’s 40.1C were all-time highs recorded at their respective weather stations.

 

Across 914 weather stations nationwide, 278 registered temperatures exceeding 35C or moshobi – “extremely hot days,” the highest level of warning until the recent introduction of the new terminology. Days over 25C are called natsubi or “summer days”, while those exceeding 30C are known as manatsubi – “true summer days.”

On Monday, a man in his 40s was found dead on a street in Sanjo, Niigata prefecture, while another in his 70s died in Kanagawa, southwest of Tokyo. Both are believed to have succumbed to the heat.

Heatstroke deaths topped 2,000 for the first time in 2024, while more than 100,000 people were taken to hospital last year between the beginning of May and late September, according to the fire and disaster management agency.

 

The rising heat is affecting many aspects of Japanese life – including yields and the quality of rice, a staple. In response, farmers are planting more heat-tolerant varieties, while some are switching to crops such as avocado that have not traditionally been grown at scale in Japan.

Impacts are also being seen in sport, with the most high-profile being the restructuring of the hugely popular koshien national high school baseball tournament. Played in the sweltering heat of August, the games have been split into morning and evening sessions since 2024 to reduce the chances of heatstroke for both players and spectators.

 

Meanwhile, office workers are being encouraged to wear shorts on hot summer days, the latest relaxing of Japan’s buttoned-down corporate culture as part of “Cool Biz” measures to reduce electricity consumption through lower use of airconditioning. Previous initiatives have encouraged “salarymen” to shed jackets and ties, and wear short-sleeved shirts but this year’s expected scorching summer has prompted calls for another level of casualness.

Tokyo governor Yuriko Koike announced the new clothing recommendations for office wear which also include polo shirts, T-shirts and trainers where appropriate, against the backdrop of expected high temperatures and a “challenging outlook for electricity supply”.

A study by the National Institute for Environmental Studies (NIES) and Tokyo’s Waseda University in 2025 found that without drastic cuts to greenhouse gas emissions, school sports will become unplayable outdoors by the 2060s.

Average summer temperatures in Japan have risen about 1.3C over the past 100 years, according to the Japan Meteorological Agency (JMA). Both 2023 and 2024 were the hottest years since records began in 1898, but last year saw those levels surpassed again. The summer of 2025 was 2.4C above the average of the previous three decades, with 132 weather stations logging their highest ever average heat and a new all-time Japanese high of 41.8C at Isesaki, Gunma, north of Tokyo, on 5 August.

'Hotter and hotter and hotter' - Europe's new climate in seven charts

 

Outdoor workers can be particularly vulnerable to the effects of extreme heat, such as that seen in the UK and Europe last month

by

Mark Poynting,Climate reporter,

Becky Dale,Senior data journalist, BBC Verify

 

 

We might only be a few days into July, but two record-breaking summer heatwaves have already provided the UK and Europe with a snapshot of their new climate.

Hot on the heels of May's heat, June saw temperature records not only broken but smashed in what the UN's weather agency called an "extraordinary" event across the continent.

And after a brief period of respite, another heatwave is on the way.

If this feels unusual, that is because it is. But it is also exactly what scientists predicted in our warmer world, driven primarily by the burning of fossil fuels releasing heat-trapping greenhouse gases into our atmosphere.

"Human-induced climate change has made events like this more likely and more intense," said Prof Stephen Belcher, chief scientist at the UK Met Office.

 The intensity of these heatwaves is evident from how far temperatures were above normal in May and June averaged across the UK, marked here in red.

 

 

While the June heat was strongest in southern England and south Wales, few areas escaped the warmth.

 

 

Temperatures peaked at 37.7C in Lingwood, Norfolk, according to provisional figures. It was one of several stations to surpass the UK's previous June high of 35.6C, set in 1957 and tied in 1976.

"To see temperatures like this in the UK in June is sobering," said Belcher.

Not every weather station has data as far back as the famous summer of 1976, but even some of the longest-running stations saw their previous records broken by 2C or more.

"We normally expect the records broken by small amounts – tenths, maybe up to a degree or so," said Ed Hawkins, professor of climate science at the University of Reading.

"So to have it shattered by such a large amount is noticeable and extraordinary, and of course this comes after a similar event in May."

 

June's heatwave may have felt particularly oppressive because it brought a double whammy of high temperatures and humidity. High humidity means it is harder for our bodies to cool down by sweating.

It also stayed very warm even after the Sun had set, making it difficult to sleep. Our bodies rely on cooler nighttime temperatures to recover from the heat of the day.

In Cardiff, temperatures did not drop below 23.5C on the night of Wednesday 24 June into Thursday – the warmest June night ever recorded around the UK.

Most of England and Wales experienced at least one tropical night in June, where temperatures do not fall below 20C. Historically, these have been very rare in the UK.

"We would definitely expect to see more and more tropical nights, as global temperatures keep rising," said Hawkins.

The same "heat dome" that brought extraordinary heat to the UK in June also saw records tumble across Europe.

The German weather service, Deutscher Wetterdienst, named it "a heatwave for the history books". The French weather agency, Météo-France, described it as "exceptional" and "historic".

More than a dozen countries across western, central and eastern Europe broke their June temperature record – with gaps of up to two or three degrees between old and new highs.

Some countries faced temperatures above 40C and set a new record for any time of year - even though June is typically cooler than July.

 

 France and Spain also recorded their hottest June days in terms of a national average, although higher temperatures had been reached before at individual weather stations.

"Compared to historical measurements, this was obviously very unusual," said Sonia Seneviratne, professor at the Institute for Atmospheric and Climate Science at ETH Zurich in Switzerland.

The Alpine nation reached 39C, surpassing the previous June record by more than 2C.

"[But] I would say as a climate scientist, I was not that surprised to see this happen... when you know that we have a warming climate," she added.

Global temperatures have been rising over the past century due to humanity's emissions of greenhouse gases, but local or regional geography shapes the speed at which different places are warming.

And as Europe is warming particularly quickly, it is more exposed to frequent and stronger spells of extreme heat.

 

Europe's rapid warming is partly the result of the melting of bright snow and ice, and a drop in the number of tiny polluting particles in the air. This means that less of the Sun's energy is reflected back into space, leaving more energy to heat the Earth's surface.

Some scientists also argue that the warming climate may be changing atmospheric circulation patterns around Europe in a way that brings more of the high-pressure systems that can lead to heatwaves, although this is not certain.

Europe's seas are exceptionally warm this summer too. Marine heatwaves conditions around the UK's coast have strengthened partly because of last week's record-breaking air temperatures.

But as water takes longer to cool down than the air, sea heat can be longer-lasting. This can help to intensify future heatwaves on land by reducing the cooling effect from sea breezes.

Scientists are certain that climate change has already made warm spells like the June heatwave significantly hotter than the same weather systems of the past.

"The only way to explain [such strong heatwaves] is to taking into account this [long-term] warming," said Seneviratne

"When you have a high-pressure system, this heatwave will tend to be much hotter [now]. This is very well understood."

 

And scientists warn that as average temperatures continue to rise, hot spells of the future will be able to reach even higher temperatures.

Only a few decades ago, the UK reaching 30C in June was a relatively rare event. Now it has become the norm.

 

The long-term warming trend across the UK and Europe does not mean that the next heatwave will be hotter than the last, nor that next summer will necessarily be hotter than this one.

But scientists warn that UK and European summers will inevitably keep getting warmer on average as carbon emissions continue to heat up the planet.

"Our heatwaves will get hotter and hotter and hotter until we get to global net zero greenhouse gas emissions [and] we stabilise the climate," said Hawkins.

Why the French are painting their windows with chalk to beat the heat

 

by Sophie Hardach

 

A simple, low-tech remedy may help cool homes. Here's the science behind the trend.

As record-breaking heat sweeps over France, some shops are running out of a simple, cheap and unexpected product – crushed chalk.

Known as Blanc de Meudon, or Meudon whiting, it is normally used to make paints or as a cleaning product. But faced with punishing temperatures, there are reports that ingenious people have been using the chalky material as a home remedy against the heat, covering windows in schools and private homes.

Mixed with water, then painted on glass, the result is a milky, whitish coating that lets in some light but reflects the heat. And a growing body of research suggests that there may be some solid science behind the DIY cooling hack.

 With heatwaves growing ever more frequent and intense due to rising global temperatures – and posing a particular danger to populations in cities – could a simple lick of white paint help people cope better when it hots up?

 

Radiative cooling

White paint – on walls and roofs, usually – is widely known to have a cooling effect. Generally speaking, white surfaces reflect sunlight and heat, while dark surfaces absorb it. This principle can be used to cool buildings and cities. Commercially available white paint on a surface can reduce temperatures on the other side by at least 1.7C (3F) compared to the ambient temperature at noon.

Paints specially developed to maximise cooling, such as ultra-white paint, have been shown to reduce the indoor temperature by several degrees by not only reflecting sunlight but also shedding heat through a process know as "radiative cooling".

One study of ultra-white paint found it could reflect up to 98.1% of sunlight, while a previous formulation reflected 95.5% of sunlight. Another study showed that combining it with a layer of ultra-black paint underneath could lower daytime temperatures by up to 7.6C (14F).

 One of the reasons why chalk might be effective, however, lies in the properties of its main component, calcium carbonate, which is not only highly reflective but also resistant to solar radiation. This property has led some researchers to use nanoparticles of calcium carbonate in new kinds of "super cool" paint.

 

"These kinds of particles are widely used in radiative cooling paint, also in our super cool paint," says Jiashuo Wang, a student at the University of New South Wales in Sydney, Australia, who is part of a team working on cooling paint.

Chalk has also been used as a coating for fabric that keeps the wearer cool. Particles of calcium carbonate – the main ingredient in chalk – are good at reflecting ultraviolet and near-infrared light (the portion of sunlight that transmits heat).

In addition, chalk is considered to be relatively benign in terms of its health and environmental impact – though there may be some risks to respiratory health from indoor chalk use, and inhaling particles.

Blanc de Meudon, or Meudon whiting, is helping the French stay cool this summer (Credit: Getty Images)

White windows and 'le cool roofing'

According to French media reports, demand for Blanc de Meudon is leading to stock shortages around the country as people struggle against temperatures of more than 40C (104F).

 

Blanc de Meudon is traditionally used to whiten shop windows during renovations or by gardeners in their greenhouses. But after the chalk-paint trick circulated on social media, demand for the product soared, French newspapers report.

"We'd known about the idea for a while, we talked about it during the last heatwave but forgot to buy any," Ouest France quotes a shopper called Philippe. "Now it's too late! It's sold out everywhere!"

Some French schools have also used the chalk paint on their windows, though an official warned that it's "not a miracle solution" and that properly insulated roofs are needed instead.

People have also whitened the windows of their apartments.

The chalk, as well as white paint more generally, is cheap. And unlike air conditioning, which worsens the overall heat effect and emissions problem by consuming energy and releasing heat outside, paint only uses energy when it's produced.

 

More like this:

• The white roofs cooling Indian slums

• The simple ways cities can adapt to heatwaves

• How to exercise safely in hot weather 

White-painted cool roofs – also known as "le cool roofing" in France – are also getting more attention there as a sustainable, low-tech way of combating extreme heat. The idea taps into a long tradition in many southern parts of Europe, such as Greece, of painting houses white to ward off the heat. 

One study suggests that cool roofs – roofs painted white or with reflective coating – could have cooled London "by about 0.8C (1.4F) on average during a heatwave, preventing the heat-related deaths of an estimated 249 people". (Read about how women in India are using white paint to cool their homes.) 

 

For those interested in another home remedy, there is an alternative: yoghurt. An experiment by researchers in the UK found that the indoor temperature of a house with yoghurt-painted windows was on average 0.6C (1.08F) cooler. They found that a thin film of the dairy product could lead to rooms being up to 3.5C (6.3F) cooler when it was "hot and sunny". While a smelly solution at first, the odour apparently disappears quickly as the yoghurt paint dries.

--

Day and night, there’s no relief: five ways this heatwave is one of Australia’s worst on record

 

It’s hard to stay cool. A tennis fan stands in front of a mist sprayer during the Australian Open Grand Slam tennis tournament in Melbourne. Photograph: Mast Irham/EPA

 Soaring temperatures, heat at altitude and hot summer nights combine to create one of south-eastern Australia’s ‘most significant’ heatwaves

by  Petra Stock

 

Heatwaves and hot days during an Australian summer may seem unremarkable. Days spent at the beach, sunburn and mosquitoes are part of the national psyche, along with outback pubs serving crisp lager as relief from searing afternoon heat.

But when the opal mining town of Andamooka (population 262) in the far north of South Australia reached 50 degrees on Thursday, it was only the eighth time in recorded history anywhere in Australia.

It was also the highest temperature recorded so far in what meteorologists have dubbed a “dome of heat” that began with exceptional temperatures in the west and moved into south-eastern Australia, where it still lingers. With no cold front to clear it out, the heat had “nowhere to go” – trapped by a blocking high in the Tasman and remnants of ex-tropical cyclone Luana in Western Australia.

 It’s difficult to compare one heatwave with another – this one came hot on the heels of one earlier in January, which scientists say was made five times more likely by global heating. During that event the fires that ignited across Victoria burnt 435,000 hectares of land (1.1m acres), and killed thousands of flying foxes in the worst mass fauna mortality event since the Black Summer of 2019–20.

 But Bureau of Meteorology senior climatologist Dr Simon Grainger says the latest heatwave is worse. For south-east Australia, it is among “the most significant we’ve ever seen”, he says, for its intensity, duration, temperatures and for the length of time the heat has remained above certain thresholds – comparable to January 2009 and January 1939.

 

Temperature records tumble

About 50 weather stations – mostly scattered across western New South Wales, western Victoria and eastern South Australia – have recorded their highest temperatures, Grainger says.

Victoria set a state all-time record of 48.9C on Tuesday in the Mallee towns of Hopetoun and Walpeup. On the same day, just over the border, the village of Pooncarie hit 49.7C, equalling the second highest temperature recorded in NSW.

Ski fields hotter than 30C

In Australia’s alps, where an average January day might be expected to reach 18C, temperatures climbed above 30C for the first time.

On 28 January, the ski town of Falls Creek recorded 30.5C, and Perisher Valley in NSW reached 30.8C – records for both places. “Those are pretty remarkable temperatures,” Grainger says.

In comparison, on the same day, Melbourne was 23.6C, and Sydney 28.5C, he says. “We were seeing higher temperatures 1,700 metres above sea level than we were [experiencing] down in Melbourne and Sydney at sea level.”

It’s one way to cool down: South Australians took to the coast for some respite. Photograph: Amer Ghazzal/Shutterstock

Hot summer nights hard to bear

Not surprisingly, during such events, the spotlight falls on record breaking heat recorded during the day. But overnight temperatures can be even more damaging.

On Monday in Adelaide, people craving relief after the mercury hit 44.7C – the city’s hottest day since 2019 – had to sweat through their hottest night since records began, with temperatures dipping to only 34.1C – about 18C above average – before quickly rising back above 40.

Dozens of inland towns and cities across South Australia, Victoria and NSW have faced five days or more above 40C. In some places, such as Albury in NSW, the heat might last for a week.

Graeme McCrabb, from the western NSW town of Menindee where temperatures reached 49.1C on Tuesday, says the heat left everyone ducking for cover. “They get off the streets, get inside and in front of air con.”

Towns including Maree in South Australia, and Wilcannia and White cliffs in NSW, sweated through three consecutive days of at least 48C, Grainger says. “For New South Wales, that’s never been seen before.”

Such prolonged heat “becomes really hard to bear, because people’s reserves just get worn down,” says A/ Prof Mark Putland, the director of emergency medicine at Royal Melbourne hospital.

“People’s houses just heat up. It gets difficult when it doesn’t cool down at night and people don’t get any relief.”

Bushfires continue across Victoria as the state experiences some of its hottest weather on record. Photograph: Michael Currie/EPA

Hospital admissions soar

Extreme heat is the most common cause of weather-related hospitalisations in Australia, killing more people than all other natural hazards combined. Stifling conditions, and sleep-less nights can be a deadly combination.

“Even while you’re asleep, extreme overnight heat can be dangerous,” warns Dr Caroline McElnay, Victoria’s chief health officer. “When temperatures stay high overnight, your body can struggle to cool down, increasing the risk of heat stress or more dangerous heatstroke.”

It’s still too early to know the full extent of the health affects, but heat-related admissions to emergency departments in Adelaide have tripled compared with January 2025, based on preliminary data.

In Melbourne, authorities issued air quality alerts warning people to stay indoors after smoke from fires burning in the Otways had drifted into the city.

Play continues at the tennis

Amid dire forecasts and heat health warnings, some of the country’s biggest sporting events carried on.

The Australian Open tennis went ahead, despite raised eyebrows, under extreme heat protocols. On the worst days, play on the outer courts was suspended and thousands of fans stayed away, which could cost the tournament an estimated $1m in lower-than-expected ticket, food and beverage revenue. Some are wondering how long it can remain feasible to hold the event outdoors in January as global heating continues to intensify.

Other events have made more substantial changes. The Tour Down Under cycling had been scheduled to traverse its most demanding stage at Willunga Hill, south of Adelaide, as the city was forecast to hit 42C, but the extreme heat and fires prompted organisers to make a last minute change to the route.

Meteorologists expect the heatwave to finally clear the country on Sunday, just as a new month begins. But hotter-than-average days and nights are likely to continue into autumn, according to the latest long-range forecast.

With additional reporting by Melissa Davey and Lisa Cox

Thousands evacuated in Spain as deadly heatwave fans Mediterranean wildfires. Boy, four, dies of heatstroke in Rome as scientists say high temperatures and fires are reminder of climate emergency

 by Sam Jones in Madrid and Helena Smith in Athens

 

The deadly heatwave fanning wildfires across the Mediterranean region has claimed at least three lives and forced thousands of people from their homes.

Firefighters continued to battle blazes on Tuesday and authorities braced for further damage as temperatures in some areas surged well past 40C. In Spain, a Romanian man in his 50s died after suffering 98% burns while trying to rescue horses from a burning stable near Madrid on Monday night.

A four-year-old boy who was found unconscious in his family’s car in Sardinia died in Rome on Monday after suffering irreversible brain damage caused by heatstroke. And in Montenegro, one soldier died and another was seriously injured when their water tanker overturned while fighting wildfires in the hills north of the capital, Podgorica, on Tuesday.

Scientist have warned that the heat currently affecting large parts of Europe is creating perfect conditions for wildfires and serving as another reminder of the climate emergency.

 

“Thanks to climate change, we now live in a significantly warmer world,” Akshay Deoras, a research scientist at the University of Reading’s meteorology department told Agence France-Presse, adding that “many still underestimate the danger”.

The fire in Tres Cantos, near Madrid – which had been fuelled by winds of 70km/h (45mph) and which has devoured 1,000 hectares of land – was still not under control on Tuesday evening, when further strong gusts were expected. The regional government said it had recovered 150 dead sheep and 18 dead horses from the area.

More than 3,700 people were evacuated from 16 municipalities amid dozens of reported blazes in the north-western region of Castilla y León, including one that damaged the Unesco world heritage-listed Roman-era mining site at Les Médulas.

Authorities in neighbouring Galicia said the largest wildfire of the year had burned through 3,000 hectares of land in Ourense province. In the southern town of Tarifa, firefighters on the ground and in planes battled a fire that broke out on Monday, with 2,000 people evacuated.

The blazes have led the interior ministry to declare a “pre-emergency phase” to help coordinate emergency resources.

Firefighters work to extinguish a forest fire in Lamas de Olo, in the Alvao natural park, Portugal. Photograph: Pedro Sarmento Costa/EPA

The prime minister, Pedro Sánchez, offered his condolences to the family of the man who died after the Tres Cantos fire, and thanked the emergency services for their “tireless efforts”.

He urged people to recognise the seriousness of the situation. “We’re at extreme risk of forest fires,” he said in a message on X on Tuesday. “Let’s be very careful.”

In neighbouring Portugal, firefighters were battling three large wildfires in the centre and north of the country.

Authorities in Greece requested EU help as fires, fuelled by gale force winds, ripped across vast swathes of the western Peloponnese and emergency services ordered the evacuation of thousands of residents.

Firefighters were also trying to contain blazes on the popular Ionian tourist islands of Zakynthos and Kefalonia. With gusts hampering firefighting efforts, emergency services ordered all hotels in the region of Agala and Keri on Zakynthos to temporarily close, forcing suitcase-wielding holidaymakers to flee and relocate to other areas.

A house burning during a wildfire that erupted in a forest near the village of Agalas on Zakynthos. Photograph: Costas Synetos/EPA

 

By late Tuesday, dozens of firefighters, supported by 15 fire trucks and eight water-bombing planes and helicopters, were still trying to douse the fast-moving flames.

“Everything that civil protection can offer is here but there are very strong winds and the fires are out of control,” said the island’s mayor, Giorgos Stasinopoulos. “We need a lot more air support, it’s vital.”

The fire service said it was also dealing with blazes farther north in Epirus, around Preveza and in the central region of Aetolia-Acarnania.

Despite temperatures nudging 43C in some parts of the Peloponnese region of southern Greece on Tuesday – and the prolonged drought, which has produced highly flammable conditions on tinder-dry soil – officials described the outbreak of so many fires as “suspiciously high”.

Faced with an estimated 63 blazes erupting and firefighters confronting flames on 106 fronts, fire officers dispatched specialist teams to several of the stricken regions to investigate possible arson.

In Albania, hundreds of firefighters and troops had subdued most of the nearly 40 fires that flared up in the past 24 hours, the defence ministry said, but more than a dozen were still active.

Since the start of July, nearly 34,000 hectares have been scorched nationwide, according to the European Forest Fire Information System. Police say many of the blazes were deliberate, with more than 20 people arrested.

The aftermath of the blaze in Çanakkale, Turkey, on Tuesday. Photograph: Anadolu/Getty Images

In Croatia, about 150 firefighters spent Monday night defending homes near the port city of Split.

In the north-western Turkish province of Çanakkale, more than 2,000 people were evacuated and 77 people treated in hospital for smoke inhalation after fires broke out near the tourist village of Güzelyalı, authorities said.

Images on Turkish media showed homes and cars ablaze, while more than 760 firefighters, 10 planes, nine helicopters and more than 200 vehicles were deployed to battle the flames. Turkey this year experienced its hottest July since records began 55 years ago.

In southern France, where temperature records were broken in at least four weather stations, the government called for vigilance.

The south-western city of Bordeaux hit a record 41.6C on Monday, while all-time records were broken at meteorological stations in Bergerac, Cognac and Saint Girons, according to the national weather service, Météo France.

Agence France-Presse contributed to this report

Grim new death records as brutal heat plagues US south-west into the autumn

Traffic warden Rai Rogers during an eight-hour shift in Las Vegas, Nevada, on 12 July 2023. Photograph: Frederic J Brown/AFP/Getty Images

 
 September has offered little reprieve after a sweltering summer, with Las Vegas on 102nd day of temperatures above 100F

 

Brutal heat continues to plague the south-west US, with excessive heat alerts lingering long into September as parts of the region set grim new records for deaths connected to the sweltering temperatures.

Autumn has offered little reprieve for cities that have already spent months mired in triple-digit temperatures. This week, Las Vegas, Nevada; Phoenix, Arizona; and Palm Springs, California, are all grappling with severe weather, with highs that have pushed over 100F (38C). More than 16 million people in the US were under heat alerts on Friday, according to the National Weather Service, mostly clustered in the southern tips of Nevada, Arizona and California.

“Late-season heat is dangerous because people are fatigued from fighting heat all summer,” the NWS forecast office in Las Vegas cautioned in an alert, which warned of extreme weather expected to last through the weekend and into next week. “This is especially true this year,” it added, “as 2024 continues to break all-time heat records.”

Fueled by the climate crisis, and often exacerbated by concrete cityscapes that cook when temperatures rise, heatwaves are getting longer, larger and more intense.

 

Las Vegas had its 102nd day of temperatures above 100F on Friday, a new record for the most days in a single year. Several states, including Arizona and California, have experienced their warmest summers on record this year, according to the National Oceanic and Atmospheric Administration, and forecasters are predicting that 2024 may rank as the hottest year – a record just set in 2023.

“But it’s not over,” NWS Las Vegas said on Twitter, noting the heat warnings lingering in the forecast through the weekend.

 The scorching and sustained heat has taken a devastating toll; heat already ranks as the most lethal weather-related disaster in the US, and deaths are increasing. Heat-associated fatalities are growing across the south-west, where shadeless streets can grow hot enough to cause second-degree burns in seconds. As dangerously hot weather stretches past summer and into spring and fall, the risks for those who don’t have access to cooling have continued to rise.

In Arizona’s Maricopa county, home to Phoenix, 664 fatalities are believed to have been linked to the heat this year , according to public health officials, who are still working to confirm more than half of them. Southern Nevada, where Las Vegas is located, has seen more deaths this year than in any year prior, with officials confirming this week that there have been 342 fatalities linked to the heat. This surpassed last year’s record, which marked an 80% increase over 2022.

But even these tragically high numbers are believed to paint only part of the picture. Heat deaths can be difficult to track, especially among high-risk populations including in unhoused communities. “We will inevitably see this number climb,” Melanie Rouse, Clark county’s coroner, told the Las Vegas Review-Journal.

Older people, children and people with underlying health conditions are among the most at risk, especially among those without access to air conditioning, but first responders have also reported that heat-related emergencies have been climbing for workers.

 “Delivery drivers, warehouse operators, our construction trades – basically anyone who has to work outside – we have seen emergencies from them and people with regular medical emergencies, and during a normal day the heat causes them to succumb,” Scott Vivier, the deputy fire chief in Henderson, a city south-east of Las Vegas, said in July.

Vivier’s department is among the first in the region to use a new tool called the polar pod, which enables emergency responders to pack someone in ice and water while they transport them to the hospital. Vivier said it’s had an incredible impact on their ability to save lives, and that they’ve even been trained to use the pods to revive overheated pets.

Exposure to prolonged extreme heat can also have lingering effects that are harder to quantify. As residents across the south-west yearn for the coming of a cooler autumn, public health clinicians have cautioned the heat can pack a psychological punch as well, leading to symptoms like irritability, anxiety and difficulty concentrating.

 

Phoenix, Arizona, hits its 100th consecutive day of 100F weather

A billboard shows the temperature in Phoenix, Arizona, on 5 June 2024. Photograph: Justin Sullivan/Getty Images
 

Hottest large city in US broke previous heat record from 1993 as temperatures are expected to reach 110 tomorrow

 

Phoenix, Arizona, saw its 100th straight day of 100F (37.7C) heat this week.

The hottest large city in the United States broke its previous record of 76 consecutive 100F days set in 1993. The relentless streak, which started on 27 May and hit its 100th day on Tuesday, is forecast to persist into next week. An excessive heat warning is in effect through Friday, with temperatures expected to reach 110F (43C) tomorrow.

This summer was the hottest one in Phoenix since 1896, when records first began. Latest county data shows that at least 177 people died from heat-related causes so far this year, with 436 under investigation. Last year, Maricopa county saw 645 confirmed heat-related fatalities, enduring 55 days in a row with above 110F temperatures.

“Summers in Phoenix are becoming increasingly hotter, with more intense and prolonged heat,” said Shel Winkley, a meteorologist at the non-profit Climate Central. “On average, Phoenix now experiences about 60 days [or] 65% of the summer with extreme heat.”

In addition to Arizona, millions of Americans across Nevada and California are facing scorching heat, with the highest temperature expected to peak in the Death Valley national park at 120F (49C).

“Temperatures will be running up to 8 degrees above normal for early September,” the National Weather Service Las Vegas office warned in an advisory.

Homeless people, children, the elderly, pregnant people and those with chronic medical conditions are at higher risk for heat-related illness.

 

“Consecutive high heat days mean that people in Phoenix don’t get respite at night, especially those who don’t have or can’t afford to run an AC unit as well as those who work outdoors,” said Juan Declet-Barreto, senior social scientist for climate vulnerability at the Union of Concerned Scientists.

“I would like the public to understand that this heat is no longer a rare occurrence,” Declet-Barreto said. “It will continue to get worse year after year if we don’t make drastic emissions reductions. We need to decarbonize our energy, industrial, agricultural and transportation sectors. There’s no way around that if we want cities like Phoenix to be livable.”

 

July was California’s hottest month in history

 

A man fishes off a jetty in Alameda, California, as the sun sets over the San Francisco Bay on 1 July.

 

Some areas see days of temperatures over 100F, drying plants and fueling wildfires as extreme heat creates deadly conditions

 

California experienced its hottest month on record in July as grueling heat baked the American west for weeks on end.

The state’s average temperature for the month was 81.7F (27.6C), according to the National Centers for Environmental Information, but some areas endured days of temperatures greater than 100F (about 38C). Several cities broke temperature records during a heatwave in early July – Palm Springs hit 124F on 5 July, while Redding in the state’s far north saw a high of 119F on 6 July.

Death Valley, the hottest place on Earth, recorded its hottest month ever in July, according to the National Park Service (NPS). In Nevada, Las Vegas reached 120F on 7 July, its hottest day in history, and set a record for number of days over 115F.

The impacts of extreme heat are being felt across the US and the world as the climate crisis drives increasingly severe and dangerous weather conditions. Last month about one-third of the US population was under warnings for record heat. The Earth saw its hottest day in recorded history on 22 July, breaking a record set just one day earlier.

A firefighter uses a drip torch to burn vegetation while trying to stop the Park fire in Tehama county on Wednesday. Photograph: Noah Berger/AP

 

Extreme heat poses major health risks and is the mostly deadly type of weather-related disaster. It is particularly dangerous for unhoused people and seniors as well as those who don’t have access to cooling spaces.

California’s high temperatures in July also helped dry out vegetation and fuel wildfires across the state. Late last month, the Park fire quickly exploded after an alleged arsonist sparked by the blaze in a city park by pushing a burning car into a ravine. The area had baked at temperatures 100F and above for days before and after the fire began. The Park fire has since become the fourth-largest blaze in state history.

 

The Pacific north-west has also endured intense heat and intense wildfires. Oregon has seen more land burned this year, more than 1.4m acres (567,000 hectares), than any year in the last 32 years, when the north-west interagency coordination center’s record-keeping began.

The extreme heat leads to more intense fires, and makes for challenging conditions for the firefighters responding to the incidents. Firefighters battling the Thompson fire last month, not far from where the Park fire broke out, suffered heat-related injuries.

Heatwaves are increasing in intensity and frequency, as well as duration and range, and are the weather events most directly impacted by the climate crisis, Dr Alexander Gershunov, a research meteorologist with the Scripps Institution of Oceanography, told the Guardian last month. He described heatwaves as “the weather extremes that are impacted by the steroids of climate change”.

“The trend is toward more frequent, more extreme, longer-lasting heatwaves all over the world,” he said. “California is certainly no exception.”