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.

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—12 pm to 6 pm. 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 3 pm and 6 pm 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 by modifying spaces but also by modifying times. Climate resilience is more than just what infrastructure cities provide—it's when it is available.

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.

By Andreina Seijas, Sciences Po.

Image: Envato

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Architecture & Design Team

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