August was the joint hottest month ever observed, tying with July 2023, as the most severe super El Niño on record amplified temperatures already heightened by global warming.

The monthly mean temperature was 1.65°C above pre-industrial levels, according to the European Union’s Copernicus Climate Change Service. Humans have not experienced temperatures warmer than this summer in the past 100,000 years, according to at Copernicus.

August was also a record-warm month for the extra-polar ocean – the regions lying just outside the Arctic and Antarctic circles – peaking at 21.1°C, the hottest temperature ever observed in the sea surface. That included unprecedented temperatures in the tropical Pacific, where winds have slackened and warm waters have been sloshing back towards the eastern Pacific, creating the strong El Niño.

“August 2026 is remarkable not simply because it’s yet another temperature record that’s been broken but because multiple parts of the climate system have reached unprecedented levels at the same time,” she says.

The records will keep being broken as the El Niño intensifies through December, she predicts, with some months likely to be as much as 2°C above average.

The record August temperature caps off western Europe’s hottest summer on record. That warmth drives extreme weather and climate catastrophes. It makes heatwaves more likely and allows the atmosphere to hold more moisture, worsening storms.

Four major heatwaves in Europe, as well as severe drought, fuelled massive wildfires near cities like Bordeaux in France and Madrid in Spain and lowered water levels in major rivers to reveal everything from long-lost woolly mammoth bones to Nazi boats.

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At least in Europe during the heatwaves than would be statistically expected, and including wheat are expected to be lower than usual.

The heat in August was also linked to a glacier collapse that destroyed several towns in Nepal and Tibet, with at least 1300 people dead and more than 5500 still missing.

“For every degree of warming, the extreme events… intensify, so in summer we get more frequent, more intense, more longer-lasting heatwaves,” Burgess says. “This obviously has a direct impact on our food security.”

In light of the temperature record, the Energy and Climate Intelligence Unit (ECIU) – a UK-based think tank – called on leaders meeting in November for the COP31 climate summit to both reverse the rise in greenhouse gas emissions and also invest more in adapting to the current impacts.

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“The task now is to match the scale of the science with the scale of action… accelerating the transition away from coal, oil and gas to bring our climate back into balance,” , international lead at the ECIU, said in a statement.

The United Nations Environment Programme said this month that the world will “overshoot” the Paris Agreement goal of preventing warming of more than 1.5°C and should now focus on reversing this warming at a later date, including with approaches like carbon dioxide removal.  

“The sooner we can bring temperatures back down, the less time we overshoot, the better it will be for our climate system,” says Burgess.

“I often get asked whether this is the ‘new normal’. The simple answer is no,” at Imperial College London said in a statement. “Until we stop burning fossil fuels, these records will continue to tumble, and the extremes will worsen faster than we are able to adapt.”

This week’s heatwave is the hottest ever recorded in Europe, as well as the most humid, and it is likely to cause thousands of deaths.

Although a potential “super El Niño” is forming in the Pacific Ocean, this didn’t play a role in the heatwave, a study by the World Weather Attribution network of scientists has found. Instead, global warming is clearly to blame.

The study analysed how likely the average daily maximum temperature projected for 26 to 28 June in western and central Europe would have been in the cooler climates of 1976 and of 2003.

While the weather pattern – a low-pressure heat dome that is trapping hot air from the south – isn’t unusual, the temperatures are. Fifty years ago, a typical June heatwave would have been about 3.5°C cooler, and the temperatures seen over the next three days would have been a less-than-one-in-10,000-year occurrence.

Daytime temperatures have 44°C  (111°F) in one French town, and nighttime temperatures have remained above 30°C (86°F) in parts of Spain.

“This event would not have been possible in June without climate change,” at Imperial College London said at a media briefing on 25 June. “The three-day nighttime temperatures would not have been possible at any time of year without climate change.”

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The humidity has also been unprecedented, reaching more than 50 per cent in many British cities. Dew-point temperatures have been in the low 20s, as compared to the single digits during the July 2022 heatwave that set the UK’s temperature record.

The wet-bulb globe temperature, which measures not just air temperature but also humidity, heat radiation and air movement, has broken or is expected to break records in almost half of European cities, the study found.

Humidity amplifies health risks because it slows evaporation, making sweating less effective. While older people or those who have a chronic illness are in particular danger, so are migrants and people experiencing homelessness.

“What we see very clearly… is how unequal the effects of this heatwave are and how that really demonstrates the inequality that widens due to climate change,” said , also at Imperial College London. “Because it’s of course people who are particularly vulnerable who are most likely to lose their lives.”

While it is too soon to look at excess mortality, a previous study found a smaller heatwave in June and July 2025 killed 2300 people in London and 11 other European cities.

“The health impacts of this heatwave are likely to be extremely high across large parts of northern and central Europe,” said Keeping.

Heatwaves will become even more intense and frequent unless we rapidly cut fossil fuel emissions, the researchers stressed. And Europe, the fastest warming continent, is not ready, as it has an ageing, urban population living in cities built for a cooler era. In the UK, only 5 per cent of homes have air conditioning.

Besides AC, Europe should invest in passive cooling like building insulation, ventilation, green roofs and walls and trees along streets, they said. It should also expand its heat response to include oft-forgotten groups like people with mental health conditions and those who are pregnant, said Carolina Pereira Marghidan at the Red Cross Red Crescent Climate Centre.

“Europe has heat action plans, but research has also shown that sometimes they do not cover all the groups that may be vulnerable,” she said.

A combination of two drugs used to treat hay fever and psychosis cooled down the core body temperature of mice and monkeys, reducing brain damage after a stroke. These medications have also undergone preliminary testing in people, and will now be evaluated in a follow-up clinical trial.

Researchers have spent decades investigating ways to chill people’s brains after they have a stroke to try to limit the damage. The idea is to freeze brain cells in a hibernation-like state so they don’t need as much oxygen and glucose when a stroke cuts off their blood supply. If brain cells can be kept alive until blood flow is restored, for example, by removing a clot, a patient may be spared from extensive brain damage and related speech and movement problems.

Unfortunately, the physical cooling strategies that have been looked at so far – including cooling blankets, ice packs and helmets – haven’t worked well. This is because they cause intense discomfort and uncontrollable shivering, says at the University of Newcastle in Australia, who wasn’t involved in the study.

Shivering is one method the body uses to “fight the induction of hypothermia”, making it hard to get body temperature down low enough, she says. “It’s great to see different cooling therapies being tested out for stroke because we know that physical cooling is just not feasible,” says Coupland.

Shuaili Xu at Capital Medical University in Beijing, China, and his colleagues administered the two drugs, promethazine and chlorpromazine, which have been known to reduce body temperature , to mice and rhesus monkeys following induced strokes.

In both animals, the drug combination led to drops in core body temperature, suppressed glucose metabolism in cells and lessened the amount of brain damage caused by the stroke. The reduced brain damage also meant the treated monkeys displayed better use of their limbs.

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Next, the team conducted a clinical trial involving 32 people who had just had a stroke. Upon hospital admission, the subjects were given the promethazine and chlorpromazine combination or a placebo, in addition to standard clot-removal therapy.

The promethazine and chlorpromazine treatment only reduced the patients’ body temperature by 0.3°C (about 0.5°F) and did not reduce stroke damage. However, Xu thinks this is because the infusions were done over 12 hours, which was too slow to bring down core body temperature by a meaningful amount. “It might have led to a low blood drug concentration per unit of time,” he says.

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His team is now launching another trial to see whether faster infusions over an hour produce stronger cooling effects and therapeutic benefits. “The fact that they’ve proven that it’s safe and these drugs are already used in humans for other indications means I think that it’s reasonable to proceed with further clinical trials,” says Coupland.

Promethazine and chlorpromazine are known to be relatively safe because they have been used for decades. Promethazine is a sedating antihistamine that can ease hay fever and assist sleep, while chlorpromazine is an antipsychotic drug used in the management of schizophrenia and bipolar disorder. They both act on the central nervous system to reduce core body temperature, without translating into shivering or subjective feelings of coldness.

Resting body temperature rises a little bit each year in women from the age of 18 to 42, for reasons that are still being figured out. The finding opens up the possibility of using temperature-sensing wearables to track ageing and detect perimenopause or potential health problems.

“We think there is a lot of information about health in the temperature signal,” says  at SRI International, a research institute headquartered in California. “We hope this facilitates investigations to identify novel markers of conditions – it may be an untapped resource of information about our health.”

Gombert-Labedens and her colleagues analysed data from a  that asked more than 750 women aged 18 to 42 to measure their oral or rectal temperature with a thermometer every day when they first woke up.

The readings showed that, on average, body temperature was lower during the first half of the participants’ menstrual cycles and higher during the second half, after ovulation occurred. Many fertility-tracking apps use this temperature jump to predict a user’s fertile window.

Gombert-Labedens and her colleagues re-examined the data in more detail to investigate the effect of age on temperature across different stages of the menstrual cycle. They found that each year from age 18 to 42, the participants became a fraction warmer, on average. As a result, those aged 35 and older tracked about 0.05°C hotter than the younger subjects across both halves of the menstrual cycle.

This is consistent with the team’s previous research that found that finger skin temperature, measured continuously by a smart ring, was  than in those aged 18 to 35.

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Further research is required to explain why this temperature increase occurs, but it probably has something to do with hormonal changes, especially towards the end of the reproductive years, says Gombert-Labedens. When perimenopause begins, temperature can increase suddenly and cause hot flushes and night sweats, but it’s unclear whether this is linked to the same mechanisms, she says.

The study only included women who did not use hormonal contraception and did not have hormonal conditions such as PMOS (polyendocrine metabolic ovarian syndrome, previously known as PCOS), so we don’t yet know how these factors might affect body temperature over time.

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Other research has found that after menopause, body temperature in women tends to  and become similar to that of men.

The higher temperature around midlife may explain why anecdotally, some women at this age say they don’t feel the cold as much as they used to, says Gombert-Labedens. “We speculate that the higher temperature in midlife women could influence their perception and reaction to environmental temperature,” she says.

As smart rings and other temperature-sensing wearables become more popular, it may be possible to identify patterns or deviations in individuals’ temperature trends that signal the approach of menopause, provide an estimate of their rate of biological ageing or detect early signs of ovarian cancer or other conidtions, says Gombert-Labedens.

The aim of limiting global warming to no more than 1.5°C is slipping even further out of reach, as the latest climate data reveals global temperatures remain extremely high, with 2025 on course to rival 2024 as the hottest year on record.

April 2025 was the second-warmest April on record, beaten only by April 2024, according to data from both the European Union’s climate change service Copernicus and Berkeley Earth, a US non-profit. Global average temperatures for the month remained at 1.51°C above pre-industrial levels, the 21st month in the past 22 to have been above that crucial threshold, . puts April 2025’s average temperature at 1.49°C above pre-industrial levels, cooler than April 2024 by just 0.07°C.

The continuing hot streak has taken scientists by surprise. 2024 was the hottest year on record, with global average temperatures reaching 1.55°C above pre-industrial levels. That was a landmark moment: the first time average temperatures had exceeded 1.5°C over a calendar year. Under the 2015 Paris climate accord, countries agreed to limit any global temperature rise to well below 2°C – and ideally to 1.5°C – above the pre-industrial level, a goal that is looking increasingly unlikely.

Scientists had expected the arrival of a cooling La Niña weather pattern in January to provide a reprieve, with temperatures expected to fall back a little this year. Instead, global temperatures have remained stubbornly high, increasing fears that 2025 could be the second year in a row above the critical 1.5°C watermark. “The recently ended La Niña event has not provided as much cooling as would typically have been expected,” said at Berkeley Earth during a briefing on 13 May.

According to Berkeley Earth’s data, this year now has an 18 per cent chance of being the warmest on record, and a 53 per cent chance of being the second warmest on record, said Rohde. There is a 52 per cent chance of 2025 having average temperatures above 1.5°C.

How the rest of the year unfolds – and what could be in store for global temperatures – now rests largely on whether a new El Niño or La Niña pattern develops in the Pacific, said Rohde.

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The continuing hot streak is further eradicating hopes that global temperatures can be limited to the 1.5°C Paris goal. The target is measured over a 20-year average, but researchers are increasingly concerned that the recent run of high temperatures means the threshold is already breached. “We are inevitably going to cross 1.5°C in the long-term average in the next decade or so,” said Rohde.

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Last year, scientists warned that three individual years where average temperatures remained above 1.5°C would mean the Paris Agreement target is lost. Similarly, a paper published earlier this year suggested that a run of 12 consecutive months above 1.5°C indicates an 80 per cent likelihood that long-term warming of 1.5°C has already been reached.

at the University of Reading in the UK says he has been surprised at the sustained nature of the warmth. Research over the past two years and the recent record temperatures have radically shifted scientific opinion on whether limiting warming to 1.5°C is achievable, he says. “Without very massive mitigation over the next 20 years, or a massive volcanic eruption, I think it’s inevitable that we have entered the period at which we do cross the 1.5°C above pre-industrial threshold.”

But he stresses that the Paris Agreement goal of limiting warming to under 2°C is still achievable. “It’s still critical that we do aim to keep temperatures below that threshold,” he says.