Urban heat islands leave some neighborhoods dangerously hotter than others

In 2020 Vienna converted Esterhazypark into its first Cooling Park, combining a misting Coolspot pavilion and mist showers (delivered with Raintime GmbH), depaving, 8,600+ perennials, and a 400+ m² green wall on the par…

The Million Cool Roofs Challenge (2019–2022) awarded 125,000 USD grants to 10 teams across 10 countries to scale reflective roof coatings, funded by the Kigali Cooling Efficiency Program (Clean Cooling Collaborative) wi…

Since roughly the mid-2010s, the Mahila Housing Trust has run a women-led cool roofs program in which residents of informal settlements paint their own roofs with solar-reflective paint. Delivery runs through women's Co…

Founded in July 2023, Giesskannenheld:innen (watering-can heroes) organizes Essen residents to adopt drought-stressed street trees and water them through dry spells. The logistical backbone is a network of 1,000-litre p…

On 11 November 2019, the Government of Türkiye planted 11 million saplings in a single day, setting a Guinness world record (most trees planted in one hour at the Çorum site), executed largely by volunteer planters. Wit…

After Ahmedabad's 2013 Heat Action Plan showed peer-reviewed mortality benefits, over 100 Heat Action Plans (HAPs) proliferated across India by 2023, mostly copying the Ahmedabad document without its coalition, accounta…

Freetown appointed Africa's first Chief Heat Officer, Eugenia Kargbo, in 2021, under Mayor Yvonne Aki-Sawyerr. The signature intervention is market shade covers in three markets, co-designed with the market women who wo…

Athens appointed Europe's first Chief Heat Officer (Eleni Myrivili) in 2021 under the Arsht-Rockefeller Chief Heat Officer program; Elissavet Bargianni has held the post since 2023. The office introduced a health-based…

In 2021 Miami-Dade County appointed the world's first Chief Heat Officer (Jane Gilbert), a post seeded by an Arsht-Rockefeller grant. The county declared an official Heat Season and published an Extreme Heat Action Plan…

In October 2021 Phoenix created the first publicly funded city heat office in the United States, the Office of Heat Response and Mitigation, under director David Hondula. The office publishes an annual heat response pla…

Marina Bay is served by what operators describe as the world's largest underground district cooling system, operational since 2006 and built into a master-planned new downtown. Central chilled-water plants supply connec…

In June 2022 Seville launched proMETEO Sevilla, the first system in the world to tie heat-wave forecasts to health outcomes and to name and categorize heat waves the way storms are named. A three-tier categorization wei…

In 2021 Miami-Dade County appointed Jane Gilbert as the world's first Chief Heat Officer — a dedicated municipal post to coordinate extreme-heat response across agencies that otherwise treat heat as no one's specific re…

After a 2010 heatwave killed 1,344 people, Ahmedabad built South Asia's first Heat Action Plan (2013) — a governance-led response combining color-coded early-warning red alerts pushed to residents, hospital "heat wards"…

Phoenix coated 36 miles of residential roadway and a parking lot with a light-gray reflective "CoolSeal" treatment and conducted a multi-year evaluation with Arizona State University — the largest cool-pavement deployme…

Begun in 2018 as part of Paris's Climate Adaptation and Resilience Strategy, "Les Cours Oasis" depaves asphalt schoolyards and replaces them with trees, permeable ground, shade and water features, then opens them as nei…

Since the 1960s 'Garden City' vision and now the 'City in Nature' / Green Plan 2030 strategy, Singapore grew green cover from 35.7% (1986) to roughly 48% even as urban density rose. Key mechanisms: mandatory greenery re…

Launched in 2016 to counter urban heat island effects and severe air pollution in the Aburrá Valley, Medellín built 30+ interconnected 'green corridors' (corredores verdes) along road verges, streams, parks and hillside…

#FreetownTheTreeTown is a community-driven reforestation program in a rapidly urbanising coastal city that lost roughly 12% of its canopy per year between 2011 and 2018, raising landslide and flood risk. Community growe…

Los Angeles, where average temperatures run nearly six degrees hotter than surrounding areas, adopted cool-surface measures alongside a measurable temperature target. Its Sustainable City pLAn set a goal to reduce the l…

After Newark recorded 103°F in June 2025 — breaking its previous June high by six degrees — New Jersey launched a $5 million Urban Heat Island Mitigation Program through the Board of Public Utilities, funded by the stat…

Seville revived a roughly 3,000-year-old passive-cooling technique, channeling air through underground galleries (a qanat-style system) to pre-cool it before delivering it to buildings and public space. The city has lon…