In charts: India is getting hotter, and the numbers make it undeniable

This year has been particularly alarming. April brought intense heat, early heatwaves and temperatures soaring past 40–45°C across several regions. On 27 April, an unprecedented development underscored the severity: all of the world’s 50 hottest cities were in India.

While rainfall in parts of the country has since brought some respite, several heat hotspots continue to record elevated temperatures.

Mint examines how severe India’s heat stress has become, how days and nights are warming, and what this means for health and productivity.

AQI.in, which tracks real-time air pollution and temperature data around the globe, noted that on 27 April, every single one of the world’s 50 hottest cities was located in India.

“Not one entry from the Middle East. Not one from sub-Saharan Africa. Not one from Australia. India occupied the entire list, from rank 1 to rank 50,” it highlighted.

Data showed that these cities were largely concentrated in Uttar Pradesh and Maharashtra, making 31 out of the 50 cities. In all of these cities, the maximum temperatures were at least 42°C, with the temperatures in UP’s Banda, Kanpur, Fatehpur, and Etawah crossing 46°C.

As a result, on 3 May, the hottest cities rankings looked different, with cities from other countries such as N’Djamena (Chad), Liwa (Oman), Al Hufuf (Saudi Arabia), Sohar (Oman), and Al Ain (UAE) entering the list.

To be sure, 45 of the 50 cities were still from India, but the list looked different. Only six cities featured again. They also recorded temperatures 0.5°C to 2.2°C lower.

However, the relief seen in early May is unlikely to last, with the India Meteorological Department (IMD) predicting above-normal temperatures in parts of southern peninsular, northeast, and northwest India. Above-normal heatwave days are also expected over some parts of the Himalayan foothills, the east coast states, Gujarat and Maharashtra.

While on a yearly basis, the temperatures have been volatile, ranging from 26.4°C to 29.2°C. However, average temperatures over longer timelines suggest an irreversible increase, with the mercury rising at a much faster pace since the turn of the century.

The temperature rose 0.44°C on average in 2001-2024 compared to the previous 50 years. The rise during 1951-2000 was only 1.44°C. From increased industrialization to global warming, several factors have contributed to this.

A study by Council on Energy, Environment and Water (CEEW) tracking ‘very hot days’ and ‘very warm nights’—instances when maximum and minimum temperatures, respectively, exceeded the 95th percentile of the 1982-2011 baseline—shows the number of such days has increased sharply over the years.

In many of these years, the number of very warm nights has surpassed very warm days. Nearly 70% of Indian districts experienced five or more additional very warm nights in the decade to 2022.

The report also points to more serious health hazards: an average Indian has been facing over six hours a day, when even light outdoor activity can pose at least moderate health risks, since 2000.

The situation has worsened in recent years, with the number of hours touching seven or even crossing the mark. The economic toll is also mounting. Compared to the 1990s, every Indian was exposed to 366 more hours of intense heat in 2024, enough to cause stress during outdoor work. Heat exposure led to 247 billion potential labour hours lost in 2024, with agriculture and construction bearing the heaviest losses.