Summer in Europe is normally cause for celebration. Not this one, however, which will rank as one of the hottest on record. Wildfires have broken out everywhere from France to Greece, while intense drought has turned the grass in London’s famous Hyde Park brown. This week, much of Europe is sweltering through yet another heatwave.
Most European cities are designed to weather cold, not intense heat. But temperatures are now regularly climbing over 35°C. Prolonged, damaging heat is forcing rapid change. Rather than abandoning normal life, urban residents put it on hold until cooler conditions arrive in the evening.
These changes are already measurable. In our recent research, we analysed two years of bank card transaction data from three Australian cities to see what happened when the temperature rose over 35°C. We found overall spending fell 7% during heatwaves. Consumers spent less between midday and early evening, before spending stabilised after sunset.
As extreme heat becomes more common, it will affect businesses and organisations in more cities. More of life will have to happen at night.
Intense heatwaves make daytime unpleasant or unsafe. But night infrastructure has to be ready. Pictured: people cooling off at a public misting fountain in Paris in June 2026.Remon Haazen/Getty
People stay home when extreme heat arrives
We used anonymised, large-scale bank card transaction data and daily temperature records from Melbourne, Sydney and Adelaide between January 2023 and December 2024. Temperatures reached 35°C or higher on 62 days over this period – 27 in Adelaide, 20 in Melbourne and 15 in Sydney. The dataset captures virtually all point-of-sale spending in three-hour intervals.
When temperatures rose above 35°C, daytime spending fell sharply, especially during the hottest part of the day – 12pm to 6pm. Some spending shifted to cooler periods, such as evenings or the days before, or after extreme heat.
Department and variety stores were among the hardest hit: despite being air-conditioned, spending was 35% lower between 3pm and 6pm on extremely hot days.
Spending on eating out, entertainment and shopping dropped off during the afternoon before recovering in the evening. Spending at convenience stores proved more resilient. Overall, some purchases were postponed but others were lost altogether.
The shift to cooler hours
Heat is no stranger to many cities around the world. But even these places are now finding it too hot.
The daily rhythm of urban life is changing in cities such as Dubai, where summer temperatures can now push past 50°C. The Middle East is warming faster than the global average. In response, authorities have opened floodlit public beaches, which remain open overnight.
In France, Paris and Toulouse have begun keeping parks, gardens and swimming areas open into the night. In Italy and Spain, tourists are increasingly exploring Rome and Seville after sunset. In Seoul, South Korea, more than 120 public libraries now stay open until 10pm to act as climate shelters.
Despite these examples, there’s little evidence of a wider shift. Authorities in many cities are not yet actively planning for a future where extreme temperatures make afternoons unpleasant or dangerous.
Most cities are still organised around a daytime model. Public transport becomes less frequent after the commuter rush in early evening, while community centres, childcare facilities and public buildings tend to close early. Parks often lack adequate lighting or safety measures to make it possible to visit in cooler evenings.
Efforts to make cities more resilient to climate change often focus on redesigning streets, cooling buildings and expanding tree plantings and other green infrastructure. These are essential. But they are only part of the story.
Cities will have to adapt not only through modifying spaces, but also by modifying times. Climate resilience is more than just what infrastructure cities provide – it’s when it is available.
In 2023, Dubai began opening beaches at night to beat daytime temperatures now topping 50°C.Government of Dubai, CC BY-NC-ND
Rethinking the city after dark
To keep cities open later, authorities will need to strengthen social infrastructure – the network of public spaces, cultural institutions, libraries, sports facilities, community centres and other neighbourhood amenities crucial to everyday life in a city.
Public libraries are well-known heat refuges. But if they close before temperatures fall, it leaves people exposed.
Creating night cities doesn’t have to mean large-scale redevelopment. Often, it’s about changing existing patterns.
Sensible measures include:
boosting frequency and reliability of public transport in evenings, especially during heatwaves
extending opening hours for libraries and other community facilities
installing better lighting along pedestrian routes
ensuring public spaces remain safe and comfortable after dark.
It’s hard for some people to shift schedules to avoid the worst of the heat. Workers with fixed hours cannot simply move their working day, while carers and parents are constrained by school and care schedules. Older adults and people with limited mobility may also depend on public transport and services that become less available after dark.
That means time-shifting will have to be accompanied by investment in accessible evening infrastructure, as well as protections for the workers needed to keep cities running later.
Nightlife – or life at night?
As extreme heat reshapes daily life in more cities, authorities must plan ahead. We will need more research on how cities can best adapt their daily rhythms to rising temperatures.
It’s common to think of a city’s nightlife as revellers visiting bars or watching performances.
But in the very near future, nightlife may come to mean something else: normal life lived at night to avoid broiling by day.
Acknowledgements: Shashi Karunanethy and Dean Magee contributed to the Australian research.
Andreina Seijas does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
So, what exactly is El Niño, why is this one potentially so significant and what could it mean for New Zealand? Here are five things to know.
El Niño begins with a huge shift in ocean heat
El Niño is a natural climate pattern involving unusual warming of the central and eastern tropical Pacific Ocean, accompanied by changes in winds and atmospheric circulation.
Here’s how the process normally works. The sun heats the tropical ocean, while trade winds push warm surface water westward across the equatorial Pacific, causing it to pile up around Indonesia, northern Australia and Southeast Asia. Cooler water rises from below in the eastern Pacific.
This build-up means sea levels in the western Pacific “Warm Pool” average about 60cm higher than in the eastern Pacific off South America. Without the trade winds holding it there, that warm water would flow back eastwards. But there is a limit to how much can build up.
Exactly how an El Niño gets underway varies, with weather and tropical storms sometimes weakening the tradewinds and providing the trigger. Once it begins, warm water starts surging back eastwards across the Pacific.
It can take two to three months to cross the ocean, shifting thunderstorms and rainfall as it goes and influencing weather patterns far beyond the tropical Pacific.
El Niño events typically occur every two to seven years, most commonly every three to five. Sea temperatures typically peak around December, with the biggest atmospheric effects occurring around February the following year.
This El Niño will be one for the record books
By December 2025, the tropical Pacific was already primed for an El Niño. Westerly wind bursts associated with tropical storms then helped set things in motion, with subsequent surges reinforcing warming towards South America.
Signs of a major event emerged early this year. Former NIWA meteorologist Ben Noll raised the prospect in February, and by July was warning it could become a very strong – or “super” – El Niño.
Higher-than-normal sea surfaces (red) are visible in the central and eastern Pacific on June 8, 2026, a few days before El Niño was declared.NASA Earth Observatory/Lauren Dauphin, CC BY-ND
Current forecasts suggest the event will continue strengthening towards the end of the year, with sea-surface temperatures in key parts of the tropical Pacific reaching more than a record 3°C above average.
It will push global temperatures even higher
El Niño is unfolding against a backdrop of human-caused warming, with global ocean heat content reaching record levels in every year from 2017 to 2025.
A 1997-98 event contributed to 1998 becoming the warmest year of the 20th century. The 2015-16 El Niño pushed temperatures to another level, while records were reset again during the 2023-24 event.
Daily sea-surface temperatures across the world’s oceans between 60°N and 60°S. The four warmest years are highlighted, including 2026 to date. Temperatures normally peak around March, at the end of the Southern Hemisphere summer, as most of the world’s ocean lies south of the equator.C3S/ECMWF, CC BY
Strong El Niño events release some accumulated ocean heat into the atmosphere, temporarily boosting global surface temperatures. Global temperatures can therefore resemble a staircase, with major El Niños helping push them onto successively higher steps.
This developing El Niño could provide the next step, with record-high global temperatures possible in 2026 and even more likely in 2027.
Exactly how climate change is affecting El Niño remains uncertain. But there are indications warming may be altering the phenomenon itself, potentially increasing the risk of very strong events.
Its impacts will reach far beyond the Pacific
El Niño has profound consequences worldwide, influencing droughts, floods, storms and heatwaves, as well as agriculture, health, fisheries, wildfire risk and economic activity.
Some effects are already emerging. Dry conditions have disrupted crops in parts of Southeast Asia and Central America, while the UN World Food Programme estimates El Niño could leave nearly 50 million more people facing acute hunger by year’s end.
Much of El Niño’s global reach comes from its influence on rainfall. Exceptionally high sea surface temperatures in the tropical Pacific shift rainfall towards the ocean, often favouring drought on land. These changes alter atmospheric circulation and weather patterns much further afield, while increasing wildfire risk in dry areas.
Changes in temperature and rainfall can affect diseases such as malaria, dengue and cholera. El Niño also shifts tropical cyclone activity, typically increasing it in central and eastern parts of the Pacific while suppressing it in the tropical Atlantic.
Weakened upwelling off South America also reduces the supply of cold, nutrient-rich water, disrupting marine ecosystems and potentially causing dramatic declines in fisheries and seabird populations.
The economic effects can linger for years, with the potential to cause trillions of dollars in losses.
New Zealand could be in for a dry year
New Zealand is already experiencing some effects of El Niño, including the relatively sunny but cold southerly conditions seen through much of this winter.
Unlike many parts of the world, New Zealand often experiences cooler conditions during El Niño.
Strongest effects typically emerge later in the year. Across the Tasman, it can contribute to drought and wildfire risk in much of Australia, with smoke plumes from fires occasionally reaching New Zealand.
El Niño tends to bring drier conditions to northeastern parts of New Zealand, particularly the North Island, while the southwest – including Fiordland and the West Coast – can become wetter.
This map shows summer rainfall during the strong 1997–98 El Niño, shown as a percentage of normal. Rainfall was well below normal across much of the north and east of both islands, while western and southern areas – particularly the lower South Island – were considerably wetter.Earth Sciences NZ, CC BY-ND
Given the potential strength of this event, there is a real risk New Zealand could experience a so-called “dry year”, with consequences for agriculture and hydroelectric generation, and an increased risk of wildfires.
Farmers and others exposed to these risks should prepare for the possibility of drought as conditions develop.
Kevin Trenberth does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Average sea surface temperature outside polar regions was 21.1C on Saturday, latest data finds
The world’s oceans were hotter than ever previously recorded on Saturday, according to the latest data.
The average surface temperature was 21.1C, with the rising marine heat a stark indicator of the climate crisis. More than 90% of the heat trapped by carbon dioxide from fossil fuel burning enters the oceans.
The Guardian’s climate forum 2026 On Tuesday 20 October, join Damian Carrington, and our panel of experts – including Professor Andy Haines, Katie White MP, Asad Rehman, Shruti Suresh Gareth Thomas and Amy Fairman for a hopeful and solutions-focused evening. Book tickets here or at guardian.live
More than 1,000 little penguins have received their first dose of bird flu vaccine in Victoria, in what is believed to be the world’s largest vaccination program involving wild birds.
Catherine Basterfield, the chief executive of Phillip Island Nature Parks, said vaccinations began early last week and were ramping up.
Backyard bird feeding is one of our country’s most popular pastimes. Research reveals about half of Australian households feed wild birds, with many people doing so daily.
However, this practice could act as a superspreader event – where a disease infects an unusually high number of people or animals – of the H5N1 virus. This deadly strain of bird flu has already decimated wild bird and mammal populations worldwide. It is now spreading across Australia, most recently killing more than 1,000 crested terns and a long-nosed fur seal, the first detection in a mainland mammal.
Although many Australians feed wild birds, the practice is controversial. This is mainly due to concerns about people offering unsuitable foods and birds becoming dependent on humans.
So why is backyard bird feeding such a problem when it comes to bird flu? And can we do it safely?
Bird feeding can attract all kinds of avian visitors.Jaana Dielenberg, Biodiversity Council, CC BY
Not just a hobby
People feed wild birds for various reasons, including to provide food during tough times or simply enjoy their presence. Most care deeply about their avian companions and believe feeding them is helpful.
However, they may not realise the danger this creates for the birds they love.
Feeding wild birds heightens the risk of disease transmission at feeding locations. When we offer supplementary food, such as seeds or meat scraps, this attracts birds of many different species in a combination and number that would not happen in nature. They may carry deadly diseases, such as the H5N1 virus, and potentially spread them to other birds.
This can create a transmission hotspot right on our back deck. And catching bird flu can push our most threatened species, such as the orange-bellied parrot, to the brink of extinction.
The fatal effects of H5N1 are not only contained to birds. Scavenger animals such as possums, red foxes and crows can be exposed to the virus while devouring the carcasses of infected birds. Humans in close contact with infected wildlife, such as wildlife carers and veterinarians, can contract H5N1. However, human infection is rare and typically only causes mild symptoms.
Wild birds don’t necessarily need the food provided by backyard bird feeders.Jaana Dielenberg, Biodiversity Council, CC BY
Stopping the spread
Backyard bird feeding may seem like a harmless hobby. But given how many people do it, and the risks it poses to both birds and people, bird feeding activities could lead to many more wildlife deaths.
So if you feed birds in your backyard, how can you do so safely?
The most effective strategy is to stop feeding birds altogether. If you don’t offer food to wild birds, they will be less likely to congregate in your backyard or garden. And they will be fine without your help. Our previous research found most birds that visit feeders obtain most of their nutrition from natural sources, such as insects and worms. So the food we provide is a snack, not an essential meal.
But if you do continue feeding wild birds, here are three precautions to take:
Offer less food
Having feeders full of seeds and leftover meat will attract more birds. So to discourage them from congregating, simply provide less food. Much like COVID-era social distancing rules, this will lower the risk of H5N1 transmission by keeping birds separate.
Avoid hand-feeding
Having a bird swoop down to snatch food from your hand is one of the most intimate interactions we can have with wildlife. But in the era of bird flu, this must stop. While humans are unlikely to contract H5N1, close physical contact with birds through hand-feeding is simply not worth the risk.
Keep everything clean
If you keep feeding wild birds, it’s vital to regularly clean all feeding surfaces and equipment using domestic bleach. If you’re not prepared to do this, you shouldn’t be feeding them at all.
Backyard bird feeding could worsen Australia’s current H5N1 crisis. Indeed, your avian visitors may complain if you give them fewer tasty treats or stop feeding them altogether. But these measures will protect both you and them from this deadly disease.
Please do not touch sick or dead birds or marine mammals. Record the location, take photographs from a safe distance, keep pets away and report the sighting to the Emergency Animal Disease Hotline on 1800 675 888.
Darryl Jones does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
