Why is New Delhi making it rain artificially?

New Delhi, India – It is that clip of twelvemonth again successful the superior of the world’s astir populous nation, erstwhile 40 cardinal radical cough and splutter done toxic contamination for weeks connected end.

These days, it is similar clockwork. At the onset of each winter, a grey haze hovers implicit New Delhi and its adjacent outer towns – a toxic mix of exhaust, smoke, and particulate that blurs skylines and stings the lungs.

It comes 1 week aft the skies were lit up with firecrackers – which added to the fumes – as radical celebrated the yearly Hindu festival of light, Diwali. Delhi’s caller government, led by Narendra Modi’s Bharatiya Janata Party, believes the reply – possibly present for mitigation, alternatively than preventing – lies successful making it rain, artificially, by “seeding clouds” successful bid to wide distant the fumes.

What is the Delhi authorities doing?

On Tuesday afternoon, a tiny craft sprinkled the clouds implicit Delhi with tiny quantities of metallic iodide and sodium chloride compounds to trigger artificial rain.

The unreality seeding proceedings aims to tackle the deteriorating aerial prime successful the nationalist superior during the wintertime months.

An craft took disconnected from Kanpur, a metropolis successful Uttar Pradesh, 500km distant from New Delhi. In consultation with scientists astatine the city’s Indian Institute of Technology (IIT) branch, it carried retired the cloud-seeding workout implicit portion of the capital.

Last week, the authorities conducted a trial formation and reported it was a success. Delhi main curate Rekha Gupta called it a “necessity” for Delhi and a pioneering measurement toward addressing New Delhi’s persistent biology challenges.

In this photograph shared by Indian Institute of Technology, a level takes disconnected from Kanpur for New Delhi for a unreality seeding proceedings to combat aerial contamination successful the capital, India, connected Tuesday, October 28, 2025 [Indian Institute of Technology, Kanpur, via AP]

Why is Delhi choking?

Every winter, Delhi’s aerial turns into a dense, toxic premix of dust, fume and chemicals.

As temperatures drop, dilatory winds and a upwind signifier called “temperature inversion” trap pollutants adjacent to the ground.

Fine particles known arsenic PM2.5, which are tiny capable to participate the bloodstream, physique up from emissions from vehicles, factories and operation dust, and harvest stubble burning successful adjacent cultivation states adds plumes of achromatic c and smoke.

These premix with gases, specified arsenic nitrogen dioxide and sulphur dioxide successful the air, to signifier new, adjacent much harmful particles. The effect is simply a grey, choking haze that blankets the city.

The deadly premix of airborne particles damages the lungs, and prolonged vulnerability has been linked to bosom and lung diseases, respiratory infections, and adverse commencement outcomes.

Diwali firecrackers lone added to the breathlessness arsenic Delhi lived up to its estimation arsenic 1 of the world’s astir polluted cities.

A idiosyncratic sprays a solution intended to wide toxic foam floating connected the Yamuna river, up of the Hindu spiritual festival of Chhath Puja, successful New Delhi, India, October 24, 2025 [Bhawika Chhabra/Reuters]

How does unreality seeding work?

In a way, it is akin to “nudging” the entity into raining. Scientists prime a unreality to “seed”, depending connected its type, its height, the presumption of the ambiance and stratification, and estimation the moisture distribution.

Then, loaded planes oregon drones spray tiny particles of salt, usually metallic iodide, into moisture-filled clouds. These enactment similar “seeds”, providing h2o vapour with thing to cling to. As much droplets stitchery astir these particles, they turn heavier until they autumn arsenic rainfall – hopefully washing distant the low-hanging contamination arsenic they do.

On Tuesday, images shared by the Indian Institute of Technology, Kanpur showed substances being released from flares attached to an craft arsenic it flew successful a cloudy sky.

Does it work?

Scientific results person been mixed. Cloud seeding cannot make earthy clouds, and the grounds that seeding reliably increases rainfall remains anemic and contested, noted Shahzad Gani and Krishna AchutaRao, professors astatine the Centre for Atmospheric Sciences, IIT Delhi, successful a file for The Hindu connected October 24.

Plus, experts interest that a important accumulation of these salts successful the ungraded aft rainfall could really beryllium harmful to the ecosystem.

The artificial rainfall tin besides lone supply impermanent respite, experts argue, against an ever-lasting occupation successful New Delhi.

“Cloud seeding is conscionable different gimmick successful a bid of akin unscientific ideas, similar smog towers, suggesting that flashy interventions tin substitute for serious, structural solutions,” Gani and AchutaRao wrote.