Can Cloud-Seeded Rain Clear Delhi’s Smog? Inside the City's Bold Plan to Tackle Toxic Winter Air

Each winter, Delhi disappears behind a thick, grey wall of smog. The air turns heavy, eyes burn, and every breath feels like work. For the city’s 30 million residents, this is an annual crisis.

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This year, the government is turning to the sky for help — literally. It plans to make it rain.

What’s happening?

The Delhi government, along with the Indian Institute of Technology (IIT) Kanpur and the India Meteorological Department (IMD), is preparing to attempt cloud seeding — a scientific process that can trigger artificial rainfall.

If the weather cooperates between 28 and 30 October 2025, specially equipped aircraft will fly over the capital’s skies and try to make rain fall where none is forecast.

The goal: to wash out the thick mix of dust and pollutants sitting over the city and give residents temporary relief from toxic air.

What exactly is cloud seeding?

Cloud seeding is like giving clouds a gentle nudge.

Normally, clouds hold tiny water droplets that are too small to fall as rain. Scientists introduce very fine particles — often silver iodide, sodium chloride (salt), or dry ice — into existing clouds. These particles act as “seeds” around which water vapour can gather and grow into heavier droplets.

When the droplets become large enough, they fall to the ground as rain.

So, it doesn’t “create” clouds; it helps existing ones release the rain they already contain.

How Delhi’s trial will work

The plan is straightforward. Aircraft fitted with special spraying equipment will disperse silver iodide into moisture-bearing clouds over parts of north-west and outer Delhi, the areas with the highest pollution levels.

Each flight can cover around 100 square kilometres.

The project — costing Rs 3.21 crore — includes five trial sorties approved by the Directorate General of Civil Aviation (DGCA), the Airports Authority of India (AAI), and the Environment Ministry. The trials will be conducted between 1 October and 30 November 2025.

If the first one succeeds, it will be India’s biggest urban cloud-seeding attempt so far.

Delhi: IIT Kanpur conducted a cloud seeding mission to trigger artificial rainfall aimed at reducing pollution levels in the city. Flares were released from an aircraft using advanced technology

(Video Source: IIT Kanpur Media Cell) pic.twitter.com/IBkqOTwBKD

— IANS (@ians_india) October 28, 2025

Why does Delhi need this?

The capital’s air quality dips to dangerous levels every winter.

Data from IQAir, a Swiss air-monitoring platform, showed Delhi’s Air Quality Index (AQI) at around 200 recently — categorised as “unhealthy.” By comparison, London’s AQI was 17 and New York’s 21.

Fine particles known as PM2.5 — the most harmful pollutant — were over 20 times higher than the World Health Organization’s recommended safe limit.

The main culprits: crop stubble burning in neighbouring states, vehicle exhaust, industrial smoke, construction dust, and cold, stagnant winter air that traps all of it close to the ground.

Rain naturally helps by clearing the air. But once the monsoon ends, Delhi often goes weeks — even months — without a drop.

Cloud seeding is an attempt to copy what the rain does best.

Does it really work?

The science says — sometimes.

Cloud seeding can increase rainfall by five to 15 percent, according to studies by IIT Kanpur and IMD. But it only works when the right kind of clouds are already in place — those with enough moisture and at the correct altitude.

Delhi’s dry winter weather often makes that tricky. Humidity needs to be at least 50 percent, and this month it’s been hovering around 20 percent.

In fact, test flights earlier this year couldn’t produce rain because the clouds simply didn’t hold enough moisture.

So, cloud seeding isn’t a guaranteed fix — it’s a chance, not a promise.

Is it safe for the environment?

Researchers from IIT Kanpur say yes. The amount of silver iodide used in cloud seeding is tiny, and there’s no evidence of harmful effects at the levels being tested. Countries like China, the United Arab Emirates, and the United States have been using similar methods for decades without reported environmental damage.

Still, scientists plan to closely monitor the process to ensure safety and transparency.

What happens if it works?

If the trial succeeds, it will temporarily bring down pollution levels by washing out suspended dust and particulate matter. It might even buy the city a few days of clearer skies.

But experts stress that this is not a long-term solution.

Once emissions continue — from vehicles, industries, and crop burning — the pollution will return.

That’s why Delhi’s government is pairing cloud seeding with other measures:

• Bio-decomposer sprays across farms to stop stubble burning
  

• EV incentives to reduce vehicle exhaust
  

• Road cleaning and construction dust control
  

• Stricter industrial emission checks under the Graded Response Action Plan (GRAP).
  

Why this still matters

Even if cloud seeding works for just a few hours, it signals a shift. It shows the willingness to try new science, involve research institutions, and act with urgency when public health is at stake.

The real goal is cleaner air, not one artificial shower. But if one rain can remind a choking city of what clean air feels like, it might just inspire bigger, lasting change.

Sources

‘Delhi govt approves 5 cloud-seeding trials at ₹3.21 crore outlay to combat air pollution’: by News On Air, Published on 8 May 2025

‘Delhi govt pushes ahead with cloud seeding, sets aside Rs 3 cr’: by The Print, Published on 8 May 2025

‘IIT Kanpur receives DGCA approval for first cloud seeding trials over Delhi’: by The New Indian Express, Published on 25 September 2025

‘Delhi gears up for first cloud seeding experiment to fight air pollution’: by Business Standard, Published on 28 October 2025

‘Delhi’s first cloud seeding trial likely today if weather permits: What we know so far’: by LiveMint, Published on 28 October 2025

‘India trials Delhi cloud seeding to clean air in world’s most polluted city’: by The Guardian, Published on 24 October 2025

‘What is cloud seeding and how it’s done: Delhi to conduct first artificial rain trial today’: by The Times of India, Published on 28 October 2025

‘Artificial rain test successful in IIT Kanpur’: by India Today, Published on 23 June 2023