What Can We Learn From This Year’s Heatwaves?

In the United Kingdom, the temperature this side of summer is finally cooler than we have come to expect, the third and longest heatwave of 2026 coming to an end. This gives us a chance to reflect on the mass disruption and unease that comes with record breaking temperatures week on week.

In the whole of the 20^th century, there were just three days where temperatures exceeded 36°c in the UK. This month we have seen three such days in under a week, and it is clear that our environment is not built to withstand this. As well as a devastatingly high number of excess deaths across the UK and Europe, extreme heat has impacted all parts of society, the economy and nature.

Coinciding with the latest ‘State of the UK Climate’ report from the Met Office, we can reflect on the June and July heatwaves and take stock of the unmistakable consequences of climate change, and what we must do to adapt.

Why are heatwaves getting worse?

It is true that heatwaves are a natural phenomenon, especially with predictable weather patterns like El Niño affecting global temperatures. However, there is now undisputable evidence that heatwaves would not be this extreme and long lasting without the effects of human induced climate change.

Greenhouse gases, originating for the most part from the combustion and extraction of fossil fuels, are the dominant driver of increasing temperatures as they change atmospheric pressure and circulation, allowing more heat to be trapped in our lower atmosphere. Usually, this excess heat would be absorbed by oceans and into soil but as the land and sea warm up themselves, their cooling qualities lose power. Nearly every day in 2025 was registered as a ‘marine heatwave day’ for the Atlantic and European seas, with temperature exceeding the 30-year average on 257 days.

Figure 1: Heatwaves and El Niño weather patterns have led to dramatic marine heatwaves for much of this year as well. Source: Copernicus Climate Change Service

These factors combined create a rapidly changing climate,  warming at a rate of 0.25°C per decade. The Met Office report tells us that changes are most visible at extremes; increasingly intense heatwaves of up to 4°C higher than last century, with risks for people, ecosystems and infrastructure which need to be addressed.

Vulnerability in the UK.

As a result, we can expect that in the next decade we will have to adapt to heatwaves and periods of dry weather, which may pose specific problems for the UK.

Heatwaves can expose vulnerabilities in society, but also in infrastructure that has been developed during historically cooler climates. During the June heatwave, 86% of people in the UK said their house became too hot to sleep, while a quarter said they had felt unwell as a result. Many buildings were never designed to cope with prolonged periods of extreme heat, and the same is seen in the rest of our built environment and infrastructure – from cooling systems and freezers to transport.

Railways in Britain for example, mostly built in the nineteenth century, can withstand ‘extreme’ temperatures of up to 30°C. But beyond this point, tracks can start to expand, while dry soil increases the risks of landslips and movements. This is an example of historically  ‘adaptable’ infrastructure which is now being placed under stress in new records of extreme heat.  

Productivity on Hot Days.

As well as placing stress on people and the environment, heatwaves are also becoming a challenge for the economy and business. Industries that rely on outdoor or physically demanding work, including construction, transport and agriculture, are particularly exposed to rising temperatures. Research from the ONS estimates that hot days (28°C and above) resulted in around £28.6 billion in lost Gross Value Added (GVA) across Great Britain between 1998 and 2021, even when accounting for existing adaptation measures, highlighting the economic importance of preparing for heatwave disruption.

Across the world, companies are already introducing earlier start times, overnight working where appropriate (for example farming), and more flexible schedules to reduce exposure during the hottest parts of the day. International standards, including guidance from the International Organization for Standardization (ISO), give some recommendations for adjusting workdays.

As heatwaves become more common, developing plans for heat risk will be a new part of business and resilience planning to help maintain safe working conditions and productivity.

Adaptation and Resilience.

Reducing greenhouse gas emissions remains essential to limiting future warming, but adaptation is becoming equally important as communities respond to the impacts already being felt. Reflecting this shift, England's Adverse Weather and Health Plan broadened their focus this year to recognise how extreme weather affects infrastructure, services, workplaces and wider society.

Many of the most effective adaptations to climate change should also deliver wider social and environmental benefits, essentially a win-win outcome. For example, expanding urban tree cover and creating shaded public spaces on one hand reduces the need for public cooling systems while also allowing more people to meet outside and cool down in parks and shaded squares, while capturing carbon.

Installing ‘green’ infrastructure like shrubs and plants on buildings and green roofs can also reduce urban temperatures while enhancing biodiversity. UK urban areas average just 18% tree cover, compared with around 30% across European cities, which show a significant opportunity for adaptation.

Another win-win strategy is the use of reversible heat pumps, which operate as renewable heating in the winter and air conditioning in the summer – replacing both gas boilers and energy hungry aircon with efficient and renewable energy.

For businesses, adaptation can be embedded through practical measures like building design, flexible working arrangements and contingency planning. The UK's Climate Change Committee has consistently highlighted the need to accelerate adaptation across sectors. By acting early, organisations can not only reduce disruption but also strengthen resilience and improve wellbeing through actions that target social and environmental goals.

Call to Action.

Membership bodies are uniquely positioned to help their members prepare for the effects of climate change by providing practical guidance, sharing best practice and advocating for policies that enable adaptation. CAFA supports membership organisations with resources and sector-specific guidance that help translate climate risks into practical actions. By working together, associations can lead their members to build resilient organisations for the future climate. Join here to access our free resources.