'Did not achieve success...’: IIT Kanpur Director explains why Delhi’s cloud seeding didn't work
The Delhi government, working with IIT Kanpur, carried out the cloud seeding operation on Tuesday as part of a larger plan to use the technology against toxic air, but Delhi’s skies remained dry
- Oct 29, 2025,
- Updated Oct 29, 2025 5:40 PM IST
Delhi’s first cloud seeding trial may not have brought rain, but it delivered valuable results for scientists and city planners confronting worsening air pollution. IIT Kanpur Director Prof. Manindra Agrawal said the experiment generated crucial data that could improve the city’s future efforts to induce precipitation artificially.
The Delhi government, working with IIT Kanpur, carried out the cloud seeding operation on Tuesday as part of a larger plan to use the technology against toxic air. Environment Minister Manjinder Singh Sirsa said the initiative marked a major step in tackling pollution, with more trials scheduled in the coming days.
Officials said the Cessna aircraft took off from Kanpur, flew over Burari, north Karol Bagh, and Mayur Vihar, and landed at Meerut Airfield. “The Cessna aircraft took off from Kanpur. It released eight fire flares, and the trial lasted for half an hour,” Sirsa said in a video statement. He added that IIT Kanpur had estimated rain could occur anywhere between 15 minutes and four hours after the trial.
However, Delhi’s skies remained dry. Speaking about the experiment, Prof. Agrawal said the team faced challenges due to low moisture levels in the clouds. “We did not get a lot of cloud moisture — only around 15%. Given the low moisture content, the possibility of rain was very small. So we did not achieve success from that perspective,” he said.
Despite the lack of showers, Agrawal said the trial yielded useful insights. “But we gathered very useful data. We had set up 15 stations across Delhi to measure air pollution and moisture levels. Our data shows a 6–10% reduction in PM2.5 and PM10 concentration, which indicates that even with limited moisture, cloud seeding has some measurable impact,” he explained.
He added that the findings will help refine future experiments,“We plan to conduct two more sorties today, and we are expecting slightly better moisture content in the clouds. Hopefully, we will have better results,” Agrawal noted.
The Delhi government formally signed an MoU with IIT Kanpur on September 25 for five cloud seeding trials, all to be conducted in northwest Delhi. The Directorate General of Civil Aviation (DGCA) has permitted these operations between October 1 and November 30.
The ₹3.21 crore project was approved by the Delhi Cabinet in May, but faced multiple postponements due to unfavourable weather conditions — first in May, then in June, August, September, and again in mid-October.
During a recent test flight over Burari, small quantities of silver iodide and sodium chloride were dispersed to induce rainfall, but with atmospheric moisture below 20% — far less than the ideal 50% — no precipitation occurred.
(With agency inputs )
Delhi’s first cloud seeding trial may not have brought rain, but it delivered valuable results for scientists and city planners confronting worsening air pollution. IIT Kanpur Director Prof. Manindra Agrawal said the experiment generated crucial data that could improve the city’s future efforts to induce precipitation artificially.
The Delhi government, working with IIT Kanpur, carried out the cloud seeding operation on Tuesday as part of a larger plan to use the technology against toxic air. Environment Minister Manjinder Singh Sirsa said the initiative marked a major step in tackling pollution, with more trials scheduled in the coming days.
Officials said the Cessna aircraft took off from Kanpur, flew over Burari, north Karol Bagh, and Mayur Vihar, and landed at Meerut Airfield. “The Cessna aircraft took off from Kanpur. It released eight fire flares, and the trial lasted for half an hour,” Sirsa said in a video statement. He added that IIT Kanpur had estimated rain could occur anywhere between 15 minutes and four hours after the trial.
However, Delhi’s skies remained dry. Speaking about the experiment, Prof. Agrawal said the team faced challenges due to low moisture levels in the clouds. “We did not get a lot of cloud moisture — only around 15%. Given the low moisture content, the possibility of rain was very small. So we did not achieve success from that perspective,” he said.
Despite the lack of showers, Agrawal said the trial yielded useful insights. “But we gathered very useful data. We had set up 15 stations across Delhi to measure air pollution and moisture levels. Our data shows a 6–10% reduction in PM2.5 and PM10 concentration, which indicates that even with limited moisture, cloud seeding has some measurable impact,” he explained.
He added that the findings will help refine future experiments,“We plan to conduct two more sorties today, and we are expecting slightly better moisture content in the clouds. Hopefully, we will have better results,” Agrawal noted.
The Delhi government formally signed an MoU with IIT Kanpur on September 25 for five cloud seeding trials, all to be conducted in northwest Delhi. The Directorate General of Civil Aviation (DGCA) has permitted these operations between October 1 and November 30.
The ₹3.21 crore project was approved by the Delhi Cabinet in May, but faced multiple postponements due to unfavourable weather conditions — first in May, then in June, August, September, and again in mid-October.
During a recent test flight over Burari, small quantities of silver iodide and sodium chloride were dispersed to induce rainfall, but with atmospheric moisture below 20% — far less than the ideal 50% — no precipitation occurred.
(With agency inputs )