Delhi’s oppressive heat has surged to dangerous levels, with a heat index – or “real feel” temperature – reaching 48.5C on Monday despite the actual air temperature being 40.8C.
The spike, driven by high humidity levels between 44 and 74 per cent, made the day feel significantly hotter than the seasonal average, according to the India Meteorological Department.
The Indian capital’s wet bulb temperature, another metric used to assess heat stress, was recorded at 28.87C. If this crosses 32C, even fit and acclimatised individuals may struggle to stay safe outdoors. At 35C, humans can no longer cool themselves effectively, risking heatstroke or collapse.
May is typically the driest and hottest month in Delhi, with low humidity and high temperatures. Experts blame a series of western disturbances, which brought cyclonic circulations and moisture incursion from the Arabian Sea, for raising humidity across northwest India.
The combination of heat and humidity has been getting worse for Delhi over the years. A new analysis by the Council on Energy, Environment and Water notes that humidity in Delhi has risen by 9 per cent since 2011.
The analysis, released on Tuesday, lists Delhi among the 10 most heat-risk regions in India, with over half of its districts now classified as “very high risk”.
“It’s not just about hotter days, nights aren’t cooling down enough, worsening heat stress for millions,” the report warns, noting that Delhi now sees six more “very warm” nights each summer than a decade ago.
Delhi’s power demand reflects the strain, hitting 7,265MW on Monday afternoon, the highest in the May 1–19 period in four years.
High population density, shrinking green cover and the dominance of concrete are feeding Delhi’s growing urban heat island effect, which traps heat and prevents night-time cooling, the report said.
This intense humid heat comes almost a year after Delhi’s Mungeshpur locality recorded a temperature of over 50C in June 2024. The weather department later said it was likely due to a sensor error, revising the figure down to around 49C.
Indian health ministry figures showed over 40,000 suspected heatstroke cases and at least 110 deaths between March and June last year, with most districts in the country facing high heatwave risk.
Experts say underreporting remains a major issue.
This year, severe conditions are once again being felt across northern India. The met department has forecast some relief for Delhi through the week, with chances of light rain and gusty winds. But high humidity is expected to persist, keeping heat stress levels dangerously elevated.
Delhi’s heatwave is part of a wider pattern. Pakistan’s Sindh province recently reported temperatures as high as 49C and multiple regions across Asia, Africa and the Americas have already experienced deadly heat this year.
The World Meteorological Organisation has confirmed 2024 as the warmest year ever recorded globally, with average temperatures 1.55C above pre-industrial levels. With oceans warmer than ever and El Niño amplifying surface heat, scientists say 2025 may continue to bring record-breaking events unless urgent emissions cuts are made.
As urban heat stress intensifies, experts emphasise the need for local heat action plans, early warning systems, and infrastructure upgrades.
Vulnerable populations, particularly outdoor workers, the elderly, and children, remain at highest risk.
Delhi may see some respite in the coming days, according to the national forecaster, as an early onset of monsoon is expected to bring temperatures down by the end of May.
