Beating the heat in
metropolitan areas

Cities like Milan and Athens are facing rising temperatures and more frequent heatwaves. The urban heat island effect makes this even worse, amplifying heat risks in densely built areas.

Heat doesn’t affect everyone equally—some neighbourhoods and some people are far more vulnerable.

This poses a challenge to the local government:

Where to act to protect residents—especially those that need it the most—from rising heat and provide cool and liveable spaces?

Illustration of a heatwave strategy — Milan
One of the biggest Metropolis of Italy located in the region of Lombardy with more than 1 million inhabitants.

Concept of urban importance — Why it matters?

Examples of urban solutions — Seven urban realities

— Heat

Case Study 2

SolutionMilan and Athens used a combination of REACHOUT climate services to find answers.

Risk

Priority

Action

Understanding the overlapping risk

Thermal Assessment Tool

The Thermal Assessment Tool revealed how heatwaves are expected to intensify over time and mapped areas with higher land surface temperatures.

This gave city teams a starting point to identify hotspots and prioritise interventions.

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Milan now has the data to show that heatwaves will become more frequent and intense over time.

Since 1981, Milan has experienced 54 heatwaves - nearly half happened in just the last decade!

Figure 1: Milan’s historical heatwaves over time - produced by Tecnalia

The longest heatwave lasted 12 days.

**Figure 2a:**
Projected heatwaves for the City of Milan under a high emissions scenario - produced by Tecnalia

**Figure 2b:**
Projected heatwaves for the City of Milan under an intermediate emissions scenario - produced by Tecnalia

Projections show that by 2060 the frequency of heatwaves will increase between threefold and fivefold.

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Milan also mapped areas with higher land surface temperatures, identifying heat hotspots.

A measure that offers a first glimpse into which communities are most exposed.

**Figure 3:**
Mean Annual Land Surface Temperature - produced by Tecnalia

Priority

Turning data into actionable priorities

Milan and Athens used the Pluvial Flood Tool to screen potential areas and identify where greening could have the greatest impact.

Heat hotspots in cities are often caused by a lack of green spaces and the widespread use of heat-absorbing materials like concrete and asphalt.

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In Milan, maps showing walking distances to large green parks helped identify which neighbourhoods lack access to green spaces and prioritise areas to reduce heat risks and support flood management.

**Figure 4:**
Walking distance from green spaces for the cities of Milan and Athens - produced by CMCC

Everybody deserves a place to cool down!

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Athens also used the CRC Tool to identify opportunities for bioclimatic regeneration, maximising the co-benefits of nature-based solutions.

In the Votris regeneration project, city stakeholders co-designed solutions to reduce heat while also improving the area’s social and environmental conditions.

**Figure 6:**
CRCTool used in the stakeholder workshop to identify regeneration options for the Votris factory and surrounding area - produced by Deltares

Action

Leaving no one behind

To make interventions more effective, Milan used The Social Vulnerability tool to combine socio-economic and demographic data with heat exposure maps.

This helped create a complete picture of neighbourhoods most at risk, incorporating social vulnerability into planning to shape actions to support the most affected communities.

**Figure 5:**
Social Vulnerability Index to heawaves in Milan – produced by UCC

The outlook for the future

The tools are already shaping policy targets and guiding decisions.

Milan is using the outcomes of the climate services to inform the “Air and Climate Plan” of the city.

Athens is incorporating the CRC tool directly into upcoming local projects like the Cooling Havens blue-green infrastructure project.

Both cities' efforts demonstrate that adapting —and ultimately thriving— with heat is a joint effort. Support and engagement from local communities and stakeholders is vital to provide a high quality of life for everyone.

Beating the heat

Insights for other local governments

City officers from Milan and Athens worked with research partners to develop tools and define their data analytic needs, helping them set an ambition and identify critical heat mitigation actions. For other cities looking to implement these or similar tools it is key to:

This collaboration ensured the data was not just technical but actionable, aligning with the cities' broader goals.

Beating the heat in
metropolitan areas

Where to act to protect residents—especially those that need it the most—from rising heat and provide cool and liveable spaces?

— Heat

Case Study 2

SolutionMilan and Athens used a combination of REACHOUT climate services to find answers.