Delhi temperatures may touch 45°C as campaigner claims paved Ghaziabad locality recorded 50°C

Delhi is bracing for another spell of severe heat, with official forecasts warning that temperatures could climb to 45°C in isolated pockets of the capital, even as environmental campaigners say people in dense urban neighbourhoods may already be experiencing far higher temperatures because of the urban heat island effect.

The India Meteorological Department (IMD) has issued a yellow alert for heatwave conditions in Delhi and the National Capital Region on May 19 and 20, 2026. It said the maximum temperature is likely to remain between 43°C and 45°C, while the minimum temperature is expected to hover around 26°C.

The warning comes a day after Delhi recorded its hottest day of the season on May 18, 2026. Safdarjung, the city’s base weather station, logged a maximum temperature of 43.4°C, about three degrees above normal. Other stations recorded even higher temperatures, with Ridge touching 44.6°C and Ayanagar 44.4°C.

Hot and dry winds are expected to continue through the week, increasing the risk of heat stress, especially for outdoor workers, children, elderly people and those with health conditions.

But an environmental campaigner says official weather readings do not fully capture the heat experienced by people in dense urban neighbourhoods.  

Akash Vashishtha, environmentalist and lawyer, claimed that temperatures recorded in an urbanised part of Ghaziabad, near Delhi, reached 50°C at noon on May 18, compared with IMD readings of 43°C-44°C from official weather stations. He provided photographs of a thermometer placed on a paved surface in Ghaziabad, which appeared to show a reading of 50°C. The claim could not be independently verified. 

Vashishtha argued that official observatories are generally located in open areas, where reflected heat can disperse more easily. In densely built-up neighbourhoods, he said, concrete, paved surfaces and closely packed buildings trap and radiate heat, creating what is known as the urban heat island effect.

“The actual temperatures felt and experienced by the human body in such surroundings can be much higher,” he said, calling for the IMD to consider additional temperature monitoring in urban localities affected by heat islands.

Urban heat islands occur when natural surfaces such as soil, grass and trees are replaced by concrete, asphalt, buildings and other hard surfaces. These materials absorb and retain heat during the day and release it slowly, keeping neighbourhoods warmer for longer, especially at night.

Experts have long warned that Indian cities are becoming more vulnerable to extreme heat because of rapid construction, shrinking green cover and extensive paving.

The effect has become more pronounced because cities that once cooled down at night are losing that ability, according to experts. Concretisation, shrinking green cover and the disappearance of water bodies have reduced the natural “heat sinks” that helped absorb and moderate temperatures. 

Delhi-NCR’s worsening heat was not only a result of seasonal weather but also of “mindless” concretisation, which he described as creating a heat multiplier effect. He called for immediate measures to restore vegetated and porous surfaces, remove unnecessary paving and increase urban greenery. 

Delhi’s expanding concrete footprint had worsened the situation, while the use of thermally poor materials such as tin sheets and galvanised iron for roofing had increased heat exposure for many residents, Mitashi Singh, programme manager for the sustainable habitat programme at the Centre for Science and Environment (CSE), previously told the English daily The Times of India.

Several cities around the world have experimented with “depaving” programmes, in which concrete and asphalt are removed and replaced with trees, gardens, rain-absorbing surfaces and community green spaces.

For now, officials have advised residents in Delhi-NCR to avoid unnecessary exposure to the sun, stay hydrated and take precautions during the hottest hours of the day. Heatwave conditions are declared when temperatures are significantly above normal and can pose serious health risks if precautions are not taken.