Heat Waves: A Long-Term Threat to Major Indian Cities, Including Mumbai

Mumbai and Other Cities Face Growing Heat Risks Amid Lack of Long-Term Solutions

Mumbai, Delhi, and other major Indian cities are grappling with increasingly severe and frequent heat waves, but a new study warns that their response remains largely short-term and inadequate. Without effective long-term strategies, India risks a surge in heat-related fatalities in the coming years.

Cities Unprepared for Long-Term Heat Resilience

A global report, co-authored by experts from the Sustainable Futures Collaborative and institutions such as King’s College London, Harvard University, Princeton University, and the University of California, Berkeley, reveals that while nine Indian cities have implemented immediate measures, they lack sustainable solutions to combat rising temperatures. The study highlights that current interventions often fail to address the root causes of heat vulnerability.

Using advanced climate models, researchers identified nine cities—Bengaluru, Delhi, Faridabad, Gwalior, Kota, Ludhiana, Meerut, Mumbai, and Surat—as the most at risk. These cities, each with a population exceeding one million (based on the 2011 Census), are projected to witness the steepest increases in hazardous heat index values, which account for both temperature and humidity.

Mumbai’s Growing Heat Challenge

With a population of 12.4 million, Mumbai is already experiencing premature and prolonged heat waves, exacerbated by high humidity. Increased humidity elevates the heat index, reducing the body’s ability to cool itself through perspiration, thereby raising health risks.

While Maharashtra has a State Heat Action Plan (HAP), Mumbai also follows its Climate Action Plan to tackle heat-related challenges. The HAP outlines preventive and responsive actions across various government departments to mitigate the effects of extreme heat. However, the study indicates that these measures are insufficient in addressing the city’s growing heat vulnerability.

Lack of Comprehensive Urban Planning

Despite progress in the health sector—such as training medical professionals and tracking heat-related fatalities—the report finds that urban planning has failed to integrate heat risks into long-term development strategies. Most cities are reacting to heat waves rather than proactively implementing resilience measures.

The study points to several challenges in implementing long-term solutions, including:

• Poor coordination among government agencies
• Shortages in technical expertise and workforce
• Lack of urgency in addressing climate risks

Call for Sustainable Heat Action Plans

The authors emphasize the need for local governments to strengthen their Heat Action Plans (HAPs) with sustainable, long-term strategies. Key recommendations include:

• Expanding cooling solutions for vulnerable households
• Introducing work-loss insurance for heat-affected laborers
• Upgrading fire management and emergency services
• Strengthening electricity grids to handle increased cooling demands

The report also highlights the role of civil society organizations in driving climate action. It found that in cities like Mumbai, Bengaluru, and Surat, sustained engagement from these organizations has successfully pushed local governments toward climate-focused policies.

As climate change intensifies, Indian cities must shift from short-term heat wave responses to long-term adaptation strategies. Without urgent action, heat waves will continue to pose a severe threat to public health and urban sustainability.