India is bracing for more intense and prolonged heat waves, impacting a larger geographical area, scientists caution. Climate change continues to exacerbate extreme weather events, leading to increased concerns about public health and resource management.
Recent climate models indicate a concerning trend: the area affected by heat waves and their duration are both expected to increase significantly across India. Krishna Achuta Rao, Head of the Centre for Atmospheric Sciences at the Indian Institute of Technology (IIT) Delhi, highlighted these findings at the India Heat Summit 2025, emphasizing that the northern plains and several southern states will likely experience longer and more expansive heat waves. What was previously a week-long ordeal could extend to a month and a half or even two months, painting a grim picture for the future.
Adding to the complexity, experts warn that these intense heat waves could also occur during the monsoon season, creating a dangerous combination of high temperatures and humidity, with the mercury exceeding 40 degrees Celsius. This scenario poses significant health risks due to the body's reduced ability to cool itself in humid conditions.
The Intergovernmental Panel on Climate Change (IPCC) has echoed these concerns in its sixth assessment report, along with other scientific publications, warning of more frequent and severe heat waves in South Asia, even during the monsoon months.
The rising temperatures are also accelerating the melting of glaciers, which Farooq Azam, a senior cryosphere specialist at the International Centre for Integrated Mountain Development (ICIMOD), warns will affect water availability in India's rivers. India relies heavily on glacial meltwater for agriculture and electricity generation, and while increased melting is currently resulting in more water, a critical threshold exists. Beyond this threshold, glaciers will contribute less water, a point known as "peak water." Some models project this could occur around 2050 for the Indus, Ganga, and Brahmaputra river basins, while other studies suggest it may have already been reached in the Brahmaputra system. Until 2050, this could also mean more floods because of increasing water.
The India Meteorological Department (IMD) has also forecast above-normal maximum and minimum temperatures from April to June, with parts of western India expected to experience seven to eight additional days of heatwave conditions this summer. While above-normal rainfall is also predicted, it's often accompanied by extreme rain events that lead to floods, creating a complex scenario of alternating heat and flooding.
In early April 2025, several cities across India recorded temperatures exceeding 40° Celsius (104° Fahrenheit), with some areas surpassing 46°C (114.8°F). Delhi experienced a three-day heat wave, with its warmest April night in three years, temperatures 5-6°C (9-10.8°F) above normal. The IMD issued a yellow alert for many areas in the northwest, indicating that the heat is tolerable but concerning for vulnerable populations like the elderly, infants, and those with chronic diseases. Parts of Gujarat were under an orange alert, advising residents to avoid heat exposure and combat dehydration.
The government of Uttar Pradesh has already instructed hospitals to prepare for heat-related illnesses, while animal shelters and veterinary teams are on alert to provide shelter and water for animals. In 2024, Rajasthan recorded a high of 50.5°C (123°F), leading to over 40,000 suspected cases of heatstroke.
While India is warming slower than the global average, a phenomenon scientists are still investigating, the increasing frequency and intensity of heat waves pose a significant challenge. As people turn to air conditioning for relief, India's energy demand is projected to peak by 2035, with an estimated 130 to 150 million new AC units.
