India Monsoon Heat Stress May Intensify And Last Longer As Global Temperatures Rise: Study

India Monsoon Heat Stress could become a far more persistent and dangerous climate threat in the coming decades, with a new scientific study warning that rising temperatures and increasing humidity during the rainy season may significantly prolong heat-related health risks beyond the traditional summer months.

The study, published in the journal AGU Advances, found that hot and humid conditions during the monsoon season could dramatically increase the occurrence of what researchers describe as “uncompensable heat stress” (UHS) under a global warming scenario of 2 degrees Celsius above pre-industrial levels.

UHS occurs when the human body can no longer cool itself effectively through sweating because of a combination of extreme heat and high humidity.

Such conditions can lead to heat-related illnesses, organ failure and, in severe cases, death.

The research was conducted by scientists from the Indian Institute of Technology (IIT) Gandhinagar in collaboration with researchers from Stanford University and Purdue University in the United States.

According to the findings, uncompensable heat stress has already become more widespread across India over the past four decades.

Between 1979 and 2021, the affected area expanded significantly, while dangerous heat conditions became increasingly frequent. Historically, the phenomenon has been concentrated during the summer months from March to June, affecting around eight per cent of the country.

In contrast, only about one per cent of India currently experiences similar conditions during the monsoon season.

However, the study projects a major shift as the climate warms.

“However, the monsoon season (July-October) UHS, predominantly characterised by hot-humid conditions, is projected to increase rapidly with climate warming and affect nearly equivalent areas of the country as the summer season,” the researchers wrote.

Under a 2°C warming scenario, uncompensable heat stress could affect around 60 per cent of India during summer and 53 per cent during the monsoon, creating an extended period of dangerous heat exposure across much of the country.

The researchers estimate that between 800 million and 1.2 billion people could be exposed to such conditions under different warming scenarios.

The study identifies the Indo-Gangetic Plain, north-western India and parts of the eastern coastline as current hotspots for extreme heat stress.

While high temperatures remain the dominant factor during summer, monsoon-season heat stress is driven primarily by elevated humidity combined with temperatures ranging between 35°C and 38°C.

Researchers noted that breaks in monsoon rainfall can create conditions that are especially favourable for dangerous heat stress events.

Scientists also highlighted that north-western India and the Gangetic Plain are likely to experience more frequent monsoon-season heat stress episodes than they currently do in summer.

The findings come as India continues to grapple with increasingly severe heat events.

Several regions recorded prolonged spells of extreme temperatures during the summer of 2026, with cities such as Ahmedabad experiencing temperatures above 40°C on most days between April and early June.

Climate researchers have increasingly warned that humidity is becoming a critical but often overlooked component of India’s heat crisis.

Previous studies have shown that oppressive heatwaves, characterised by both high temperatures and high humidity, are increasing faster than dry heatwaves and are more strongly linked to heat-related mortality.

Experts say the latest findings underline the need for stronger adaptation measures, including heat action plans, urban cooling strategies, improved public health preparedness and better protection for outdoor workers.

As global temperatures continue to rise, the combination of heat and humidity is expected to place growing pressure on public health systems, labour productivity and climate resilience across one of the world’s most densely populated regions.

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