Assessment Reveals How Brazilian Cities Are Preparing for Extreme Heat
Key Findings
Most of the 53 participating Brazilian cities surveyed through the Beat the Heat initiative recognize extreme heat as a critical threat to both residents and urban systems. However, many remain in the early stages of planning, with fragmented responses and limited implementation capacity.
Current efforts are concentrated primarily on green infrastructure measures such as urban tree planting and the creation of shaded areas. While these solutions are important, they are insufficient on their own. Integrated policies, data-driven decision-making, risk prioritization, continuous monitoring, and structural measures related to buildings, housing, transportation, and public procurement remain relatively uncommon.
Limited financial resources, shortages of specialized personnel, and heavy reliance on external support continue to be the main barriers to progress. These challenges hinder both integrated planning and policy continuity, underscoring the need for greater investment, capacity building, and stronger governance mechanisms to address increasingly intense heat waves.
Access the full assessment here.
Extreme heat, often perceived as little more than a summer inconvenience, has become a silent and deadly threat. Today, it causes approximately half a million deaths worldwide each year—roughly one life lost every minute—and that figure could double over the next three decades. In Brazil alone, heat waves caused an estimated 50,000 deaths in metropolitan areas between 2000 and 2020, far exceeding fatalities associated with flash floods and landslides. The impacts affect everyone, from vulnerable populations to otherwise healthy individuals exposed to prolonged outdoor work or poorly ventilated environments.
As recent years rank among the hottest ever recorded, cities around the world are beginning to respond. Against this backdrop, participation in Beat the Heat—a partnership between the COP30 Presidency and the United Nations Environment Programme (UNEP), which leads the Cool Coalition—continues to grow and gain momentum. The initiative currently brings together more than 250 cities, including 105 in Brazil, alongside over 100 institutional partners worldwide.
In Brazil, Beat the Heat is supported by the Ministry of Environment and Climate Change through the Green and Resilient Cities Program. By strengthening urban planning, promoting nature-based and passive cooling solutions, and encouraging sustainable public procurement, participating municipalities aim to reduce immediate risks while building resilience for a future that is projected to become increasingly hotter.
The survey of 53 Brazilian cities participating in the initiative shows that extreme heat is already widely recognized by local governments: 93 percent classify it as a significant concern, and 68 percent rank it among their three most pressing local challenges. Yet recognition has not translated into readiness. Most cities remain in the early stages of planning, face significant gaps in data and governance, and depend heavily on external financing to move forward.
“Extreme heat is a slow-onset disaster that is undermining the livability of cities, communities, and territories, forcing billions of people to adapt their daily lives. Students miss classes, athletes alter their training routines, and construction workers have to adjust their shifts to avoid the most dangerous hours of the day. Responding to this new reality demands collaboration across all levels of government and sectors of society, with strong national and international support. That is precisely the purpose of the Beat the Heat initiative,” said Ana Toni, CEO of COP30.
Extreme heat is not simply "a very hot day." It occurs when heat accumulated during the day is not dissipated overnight for two or more consecutive days. Temperatures build progressively in a staircase effect—something many people have experienced when homes fail to cool after sunset, heat radiates from pavement, sleep becomes more difficult, and energy levels decline. As this cycle continues, people, buildings, water systems, energy infrastructure, and agriculture lose their ability to recover, while risks to public health and urban functioning increase rapidly
Addressing this challenge requires cities to rethink infrastructure, expand green and shaded areas, reduce heat retention in urban surfaces, improve ventilation, minimize waste heat from equipment, and strengthen health and emergency services. These efforts must be supported by robust forecasting, early warning, and public information systems to ensure communities know how to prepare for, respond to, and recover from extreme heat events.
The survey found that 66 percent of cities have either not yet begun or are only just beginning to develop action plans, while 75 percent do not use data systematically in decision-making. Although 60 percent have established a focal point or dedicated department responsible for the issue, only 42 percent use geographic information systems (GIS) to map risks. Furthermore, 85 percent rely on external funding to implement measures.
Among the most common actions are nature-based solutions—including urban forestry, parks, green roofs and walls, river and wetland restoration, retention ponds, and bioswales—which are being implemented by 77 percent of responding municipalities. By contrast, relatively few cities have adopted passive cooling strategies in buildings and urban spaces, such as cross-ventilation, reflective surfaces, permeable pavements, and thermal insulation, with adoption rates of 21 percent or less. Another significant gap remains sustainable procurement: more than 80 percent of municipalities have yet to establish public purchasing criteria that support cooling objectives.
Created in 2025, Beat the Heat aims to support cities in conducting assessments, developing action plans, strengthening local capacities, and mobilizing financing. Inspired by the Brazilian concept of a mutirão—a collective effort organized around a shared purpose—the initiative connects international commitments with concrete local action, prioritizing municipalities and populations most vulnerable to the impacts of climate change.
The next 12 to 18 months are expected to bring significant progress. Fifty-one percent of participating cities plan to develop comprehensive municipal policies on extreme heat, 21 percent intend to deepen risk and vulnerability assessments, and 28 percent aim to implement interventions in high-risk areas or strategic public assets. Together, these actions could benefit an estimated 7 million people among the approximately 50 million residents living in the 53 participating cities.
The urgency of this work is reinforced by recent projections from Brazil's National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN), which indicate the possible development of a "Super El Niño" during the second half of 2026. Such a scenario could intensify droughts and wildfires in northern and northeastern Brazil, increase the frequency of heat waves across central regions, and trigger extreme rainfall in the south. According to climatologist José Marengo, the phenomenon is expected to peak between December 2026 and January 2027, with noticeable impacts beginning as early as spring and direct consequences for water and energy systems.
By translating climate commitments into practical action, Beat the Heat is helping protect lives, reduce inequalities, and strengthen climate adaptation, while establishing one of COP30's most tangible implementation legacies on the ground.
Learn more about Beat the Heat
Click here and access the registration form to join the initiative
The Beat the Heat assessment was presented during a technical visit to Rio de Janeiro’s Operations and Resilience Center (COR) on June 3, where city officials and initiative partners exchanged lessons and experiences on Rio’s pioneering Extreme Heat Protocol. The protocol is featured as part of UNEP’s newly launched 50@50 initiative.
About the 50@50 Initiative: 50@50 is a global campaign under Beat the Heat that showcases 50 cities taking action to prepare for a hotter future. The initiative highlights cities that are acting before temperatures reach dangerous levels, demonstrating how leadership, innovation, and forward-looking planning can reduce risks and protect communities. By sharing real-world examples, 50@50 promotes solutions such as nature-based interventions, sustainable cooling, resilient infrastructure, and climate-smart urban design.
Featured cities include:
Brazil: Fortaleza, Teresina, Campinas, Rio de Janeiro
Global: Paris, Barcelona, Antalya, Lagos, Melbourne, Jakarta, Santiago, Mendoza, Yangzhou
Beat the Heat is also a flagship initiative of Axis 4—Building Resilience for Cities, Infrastructure, and Water—within the Global Climate Action Agenda. As part of this effort, partners are developing a Plan to Accelerate Solutions titled “Greening Cities to Beat the Heat: Harnessing Nature-Based, Passive, and Efficiency Solutions for Sustainable Cooling and Energy Demand Reduction.” Learn more about the PAS.