Standfirst: Guimarães, named European Green Capital 2026, is using trees, water-sensitive design and public-space changes to reduce urban heat. The Portuguese city’s experience highlights how local action can support wider EU climate goals.
Extreme heat is becoming a growing challenge for European cities, but one Portuguese municipality is testing practical ways to make urban life safer and more comfortable. Guimarães, the European Green Capital 2026, has reduced temperatures in parts of the city by around 2°C through changes to streets, public spaces and green infrastructure.
The project offers a local example of wider European climate policy in action. While national governments and EU institutions set emissions targets, cities are responsible for many measures that directly affect residents, including shade, drainage, transport and the design of public spaces.
How Guimarães is reducing urban heat
Guimarães has focused on adapting the built environment rather than relying solely on air conditioning. The city has introduced more vegetation and redesigned areas where heat can accumulate, helping to lower surface and air temperatures during hot weather.
Measures highlighted in the city’s approach include:
- Planting trees and expanding shaded areas;
- Using greener public spaces to replace heat-absorbing surfaces;
- Improving urban design to support airflow and cooling;
- Managing rainwater more effectively through nature-based solutions;
- Encouraging residents to use public areas that are safer during periods of extreme heat.
The reported temperature reduction does not mean the entire city is uniformly 2°C cooler. Local effects vary according to materials, shade, vegetation and exposure. However, the result illustrates how targeted interventions can make a measurable difference in particular neighbourhoods.
Why urban heat matters across Europe
Heat is often more intense in cities because roads, roofs and buildings absorb solar energy and release it slowly. This “urban heat island” effect can leave built-up areas warmer than nearby rural locations, particularly at night.
That matters for public health. High temperatures can increase risks for older people, babies, outdoor workers and those with existing heart or respiratory conditions. Heat can also raise electricity demand as households and businesses use more cooling, while dry conditions put additional pressure on water supplies and urban vegetation.
European cities face different risks depending on their climate and geography. Southern municipalities are frequently exposed to prolonged heat and drought, while cities farther north are increasingly preparing for short periods of unusually high temperatures. Heavy rainfall can also follow hot, dry periods, making drainage and permeable surfaces important parts of climate adaptation.
From European Green Capital to long-term policy
The European Green Capital award recognises cities that demonstrate environmental ambition and practical progress. The designation is not an EU law and does not automatically require other municipalities to copy the winning city’s programme. Its value lies in showcasing approaches that may be adapted elsewhere.
Guimarães has used the title to draw attention to the connection between climate adaptation, biodiversity and quality of life. Cooler streets can make walking more attractive, while tree planting can provide shade, support wildlife and improve the visual character of neighbourhoods.
Urban greening can also contribute to broader European climate objectives, including reducing emissions, improving resilience and making the transition to a low-carbon economy more visible in everyday life. Yet such projects require maintenance, long-term funding and careful planning. Trees need water, public spaces need upkeep and poorly designed planting schemes can create problems during drought.
What other cities can learn
The Guimarães example suggests that urban climate policy works best when it combines several interventions rather than depending on a single solution. Cities considering similar projects should assess:
- Which neighbourhoods face the greatest heat exposure;
- Where trees and shade would provide the largest public benefit;
- How projects can conserve water during dry periods;
- Whether pavements and roads can be replaced with permeable materials;
- How residents will be involved in the design and maintenance of public spaces;
- How progress will be measured over time.
There are also social questions. Green improvements should benefit areas with the greatest health and environmental needs, not only city-centre districts or high-value developments. Affordable access to shade, parks and cooler public buildings is an important part of a fair climate response.
What does this mean for Ireland?
Ireland is not facing the same long-term heat profile as southern Portugal, but Irish towns and cities can still experience dangerous heat, especially during prolonged warm spells. Urban greening, shaded routes and better rainwater management could help local authorities prepare for more variable weather.
The Irish relevance is therefore practical rather than a direct legal consequence. Guimarães’ work provides an example of how municipalities can connect climate adaptation with transport, public health, biodiversity and planning policy. It also shows why climate action is not limited to national emissions targets or EU legislation.
The wider lesson for European climate policy
National and EU climate strategies often focus on energy systems, transport emissions and industrial pollution. Those areas remain essential, but adaptation determines how people experience climate change in their daily lives.
Cooler streets will not prevent heatwaves, and urban planting cannot replace emissions cuts. They can, however, reduce exposure and improve resilience when combined with cleaner energy, efficient buildings and responsible water management.
Guimarães’ experience demonstrates that city-level decisions can turn broad climate objectives into visible changes. The central takeaway is clear: European climate policy will be judged not only by targets and legislation, but also by whether homes, streets and public spaces remain liveable as temperatures rise.