At 10:30 AM on October 30, 2025, two modified Beechcraft King Air C90s took off from a Delhi airbase, carrying 120 kilograms of silver iodide crystals—each grain a desperate hope for rain in a city choking on its own breath. Delhi’s Air Quality Index had just hit 486, the highest possible level, with PM2.5 concentrations at 382 µg/m³, more than 75 times the WHO’s safe limit. The government wasn’t just reacting—it was betting ₹7.85 crore on a weather experiment that had failed twice before.
Why Now? The Air Wasn’t Just Bad. It Was Deadly.
Delhi hasn’t just had a bad week. It’s had 17 straight days of hazardous air since October 13, 2025. The Central Pollution Control Board’s Anand Vihar station recorded levels so high, schools were shut, hospitals saw a 40% spike in respiratory cases, and elderly residents were told to stay indoors. Vehicular emissions accounted for 41% of the pollution; stubble burning from Punjab and Haryana added another 29%. The rest? Construction dust, industrial fumes, and the ever-present smog that clings to the city like a second skin.
What made this day different? Weather. The India Meteorological Department (IMD) gave the green light after confirming 65-70% cloud cover at 1.5–2.0 km altitude and 78% humidity—conditions Dr. M. P. George, IMD Director, called "optimal for artificial rain induction." For the first time in years, the sky wasn’t just polluted—it was ready to give back.
The Science Behind the Rain Machine
Cloud seeding isn’t magic. It’s physics, refined. The two aircraft, operated by the National Atmospheric Research Laboratory (NARL) from Gadanki, Andhra Pradesh, use CL-800 generators to spray silver iodide into supercooled clouds. At -5°C, these crystals act as ice nuclei, forcing water vapor to freeze and fall as rain. Professor Sachchida Nand Tripathi of IIT Kanpur, who led the scientific validation, explained: "We’ve mapped three convergence zones—South Delhi, North Delhi, and the Yamuna floodplains—where rainfall probability exceeds 40%. That’s the target."
The silver iodide? Sourced from Merck Specialties Private Limited in Mumbai at ₹6,542 per kilogram. Each aircraft carries 60 kg—enough to seed clouds over 1,484 square kilometers. The Ministry of Earth Sciences (MoES) has allocated ₹15.2 crore for the entire 2025–2026 season, with ₹3.7 crore dedicated to 12 Doppler radars monitoring real-time atmospheric shifts. This isn’t a one-off stunt. It’s a calibrated, data-driven campaign.
Who’s In Charge—and Who’s Skeptical?
Chief Minister Arvind Kejriwal, chair of the Delhi Disaster Management Authority (DDMA), announced the operation from the Delhi Secretariat at 9:15 AM. "If successful," he said, "we could reduce PM2.5 by 25–30% within 24 hours." The DDMA, working with IIT Kanpur and MoES, has been preparing for this since last winter’s failed attempt.
But not everyone’s convinced. Dr. Anumita Roychowdhury of the Centre for Science and Environment (CSE) in New Delhi offered a sobering counterpoint: "Cloud seeding gives temporary relief, like putting a bandage on a broken leg. We need to stop burning 13,000 tons of crop residue every day and replace 1.2 million diesel vehicles in Delhi." Her point is simple: if you don’t fix the source, the smoke returns.
Even the Indian Air Force is involved. A temporary restricted airspace (NOTAM IND1234/25) has been enforced between 1,500–3,000 meters over Delhi, with aircraft broadcasting the ID DEL-SEED1 under MoES file number MoES/CCER/2025/8876. This isn’t just weather modification—it’s a coordinated national operation.
What Happens If It Works?
Success is defined narrowly: at least 2.5 mm of rainfall over 50% of Delhi’s area. If achieved, the DDMA will immediately schedule follow-up missions on November 4, 7, and 10, 2025—pending weather permits. The goal isn’t to cure pollution, but to buy time. For schools to reopen. For hospitals to catch their breath. For the public to feel like they’re not suffocating.
Historical context matters. This is Delhi’s third cloud seeding attempt. The first, on November 15, 2023, failed due to only 45% cloud cover. The second, on December 2, 2024, collapsed under wind shear. This time, the data is better. The coordination is tighter. And the stakes? Higher than ever.
Is This the Future of Urban Air Quality?
Delhi isn’t alone. China has used cloud seeding for decades, especially before major political events. Dubai has spent hundreds of millions on it to fight drought. But for a city with 30 million people, no clean air infrastructure, and no political will to shut down polluting industries, artificial rain is the only tool left.
Experts say it’s a stopgap, not a solution. But when the air is killing children, stopgaps become necessities. The real test won’t be whether it rains today. It’ll be whether Delhi’s leaders use this moment to finally tackle the root causes—or just wait for the next crisis.
Frequently Asked Questions
How does cloud seeding actually create rain?
Cloud seeding doesn’t create clouds—it helps existing ones release rain. Silver iodide crystals are released into supercooled clouds (below -5°C), acting as nuclei that attract water vapor. This triggers freezing and precipitation. The process only works if clouds are already moisture-rich and at the right altitude, which is why weather permits from the IMD are critical.
Why did previous attempts fail in 2023 and 2024?
The 2023 trial failed because cloud cover was too low (only 45%), meaning there wasn’t enough moisture to seed. In 2024, wind shear—sudden changes in wind speed or direction—tore apart the cloud formations before precipitation could form. This year’s operation benefited from advanced radar monitoring and precise timing based on IMD’s real-time data.
Who is responsible for monitoring the operation?
The National Atmospheric Research Laboratory (NARL) operates the aircraft, while IIT Kanpur provides scientific oversight. The India Meteorological Department (IMD) grants weather permits and tracks atmospheric conditions. Twelve Doppler radars across the National Capital Region feed real-time data to a central command at the Ministry of Earth Sciences, ensuring every decision is evidence-based.
What’s the long-term plan if cloud seeding works?
If today’s trial produces measurable rainfall, the Delhi Disaster Management Authority plans expanded operations on November 4, 7, and 10, 2025. But officials admit this is a temporary fix. The real strategy—still under development—must address 13,000 tons of daily crop residue burning and replace 1.2 million diesel vehicles in Delhi, which together account for 70% of pollution.
Is silver iodide harmful to health or the environment?
According to the World Meteorological Organization and MoES, the amount used—120 kg—is far below environmental thresholds. Silver iodide occurs naturally in trace amounts and is not toxic at these concentrations. Studies show no measurable impact on soil, water, or human health after decades of global use. Still, independent monitoring is ongoing.
Could this become a regular tool in Indian cities?
Possibly. Cities like Mumbai, Kolkata, and Lucknow face similar pollution crises. But cloud seeding requires specific meteorological conditions and significant funding. Without strong political commitment to reduce emissions at the source, it’s a Band-Aid. Experts warn that scaling this nationally would require ₹500+ crore annually—money better spent on public transport, clean energy, and farm waste management.