Heatwave Grips India: Is El Niño To Blame?

This summer has brought India to its knees, with record-breaking temperatures soaring as high as 47.6°C. The severe heatwave has engulfed large parts of the subcontinent, with several cities simultaneously recording extreme temperatures. As the government warns that these conditions are likely to persist until June, the country is bracing for a prolonged spell of intense heat.

As temperatures continue to soar, data from AQI.in's real-time trackers shows that 95 of the world’s 100 hottest cities are in India. Several heatstroke-related deaths have already been reported across the country this April, from Odisha to southern states like Kerala and Karnataka.

Cities in Chhattisgarh and Uttar Pradesh dominate the list of the top ten hottest cities, with northern states bearing the brunt of the heatwave. Temperatures there have consistently hovered in the late 40s.

The India Meteorological Department (IMD) has issued repeated advisories urging people to avoid stepping out during peak hours and to stay hydrated. The advisory cautions, “Extended hot days can lead to various impacts, including increased risk of health issues like heatstroke, higher electricity consumption and water shortages”.

A Different Kind of Heat

Terming the heat as “unusual”, Joy Merwin Monteiro, Assistant Professor at Indian Institute of Science Education and Research (IISER), Pune, explains to Outlook, “IMD’s bulletin has noted on a national level the heatwave. For the past three years, including this one, we have been conducting measurements on campus and have observed that this April has shaped up to be quite warm.”

Monteiro points out that while last year’s summer was “extreme as well, this year's summer has turned out to be extreme in a different sense”. He explains that the summer of 2025 saw short bursts of intense heat, whereas this year has been marked by prolonged and sustained high temperatures.

He adds that India is particularly vulnerable to heat stress due to its monsoonal climate, where high pre-monsoon temperatures are typical. However, human-driven factors are worsening the situation.

Concurring with this, Dr Abhilash S, Director and Associate Professor at the Advanced Centre for Atmospheric Radar Research, CUSAT, says, “The heat stress we are currently experiencing cannot be attributed only to natural causes. In the name of urban development, away from green cover and wetlands are being encroached upon, which would have normally acted as a buffer in the face of heat.”

Distinguishing between green cover and natural forests, he notes that native forest canopies play a crucial role in cooling, yet are steadily being lost to urban expansion.

India and El Niño

To explain the extreme temperatures, some reports have pointed to the possibility of a “Super El Niño”.

Now, El Niño is a natural climate phenomenon that occurs every two to seven years, caused by the warming of ocean surface temperatures in the central and eastern Pacific. A stronger-than-usual event—often termed a “Super El Niño”—can intensify global heat.

However, both Monteiro and Abhilash caution against attributing the current heatwave solely to this phenomenon.

“The present ongoing heatwave is not due to El Niño,” says Dr Abhilash, “El Niño is still evolving. What we are seeing right now is due to the anti-cyclonic pressure over central and northern India, which is acting as a sort of 'heat dome', as well as the limited Western disturbance rainfall from last year, and global warming.”

At the same time, he warns that the possibility of a stronger El Niño event cannot be ruled out. “ We will have to wait and watch to be super about the Super El Niño. India has witnessed two of these events in the past, in 1997-1998 and 2015-2016, which created a large-scale drought situation. Based on this historical data, there can be a reason to look out for a Super El Niño event.” He adds that even a regular El Niño contributed to 2024 being one of India’s hottest years, suggesting that a stronger event could push temperatures even higher.

Monteiro echoes this uncertainty: “There is no consensus on a Super El Niño this year, as not all the forecast models are predicting a strong El Niño. However, they all do predict that there is 90% to 100% chance of an El Niño effect this year.”

He adds, “That is the only indicator I can point to right now for this pre-summer heatwave is that developing El Niños have started becoming warmer and accelerated over the past month. The Indian subcontinent, including Pakistan and Bangladesh, is geographically quite responsive to the Tropical Pacific Ocean temperatures.”

Dr Rajib Chattopadhyay from the Indian Institute of Tropical Meteorology (IITM) notes that El Niño develops gradually over time and points to additional factors driving the current heat.

A joint study by IITM and IMD identifies two types of heatwaves in India: dry and moist. Dry heatwaves primarily affect northern states, while moist heatwaves—characterised by high humidity—are more common in coastal regions and cities like Chennai. These conditions are further intensified by warming in the Bay of Bengal.

How heat impacts your health 

The Ministry of Health and Family Welfare has directed states and Union Territories to operationalise dedicated heatstroke management units, ensure ambulance preparedness, issue early warnings, and maintain real-time reporting of heatstroke cases.

Yet, these measures may not be enough—particularly for economically vulnerable populations who continue to work outdoors in extreme conditions.

According to HeatWatch, 84 heatstroke deaths were recorded in the summer of 2025. Data from the Union Ministry of Home Affairs shows that 11,868 people died due to heatstroke in India between 2012 and 2022, underlining the growing severity of heat-related health risks.

Apekshita Varshney, founder of HeatWatch, argues that the impact of heat is less about geography and more about inequality.

She says, “The assumption that "urban = protected" collapses the moment you look within cities. Wealthier neighbourhoods tend to have more tree cover, better planned infrastructure, green spaces, and access to air conditioning — they are measurably cooler. Informal settlements and dense working-class neighbourhoods, by contrast, have high-density housing, metal rooftops, little to no vegetation, and workers who must be outdoors regardless of the temperature.”

She adds, “Our research at HeatWatch has consistently shown that garment workers, construction workers, waste pickers, and gig delivery workers in cities like Delhi NCR, Hyderabad, Dindigul, Rohtak, Bengaluru bear a disproportionate heat burden — not because the city is hotter than the village, but because their work offers no protection and their neighbourhoods offer no relief.”

As India begins to record the first fatalities of this summer, responses from those in power have also drawn attention. Union Minister Jyotiraditya Scindia, while addressing the public in Madhya Pradesh, shared his personal approach to coping with the heat—pulling out an onion from his pocket and encouraging others to do the same.

If such responses are any indication of the broader approach to the crisis, it raises a larger question: is India adequately prepared to deal with the growing threat of extreme heat?

With temperatures expected to remain high in the coming weeks, the need for that answer grows.