29 October,2025 07:51 PM IST | New Delhi | mid-day online correspondent
A Cessna aircraft released cloud-seeding flares in different areas of Delhi on Tuesday. Pic/PTI
Indian Institute of Technology (IIT)-Kanpur director Manindra Agrawal on Wednesday said that while the recent cloud-seeding trials in Delhi did not result in rainfall, the exercise provided valuable scientific data. He also highlighted that the cost of conducting such trials was modest compared to the large sums spent on pollution control measures in the city, news agency PTI reported.
The Delhi government, in collaboration with IIT-Kanpur, conducted two cloud-seeding trials on Tuesday in Burari, North Karol Bagh, and Mayur Vihar. Despite the efforts, no substantial rainfall was recorded, although minimal showers occurred in Noida and Greater Noida.
"The trial was conducted over an area of 300 square kilometres. The overall cost, in my rough estimate, came to around Rs 60 lakh. This roughly comes to about Rs 20,000 per square kilometre. If we conduct the exercise over an area of 1,000 square kilometres, the cost would be around Rs 2 crore," Agrawal explained in a video statement.
He further added that if cloud seeding is carried out over the entire winter season, assuming clouds are present once in 10 days, the total expenditure would amount to approximately Rs 25 to 30 crore, PTI reported.
"In the overall scheme of things, this is not a very large amount. The money spent on pollution control in Delhi is much higher," he said.
Agrawal noted that the low moisture content in clouds significantly reduced the chances of inducing rainfall, PTI reported.
"The moisture content was only around 15 per cent. With such low moisture, the possibility of making rain is very low. While we did not achieve rainfall this time, we obtained a lot of useful information for future trials," he said.
He added that 15 monitoring stations were set up at different locations to measure air pollution and moisture levels.
"We observed some reduction in PM2.5 and PM10 concentrations. Even with low moisture, cloud seeding does have some effect, although not as much as ideally desired," Agrawal explained.
During the trials, a finely ground mixture of common salt, rock salt, and silver iodide was injected into clouds to induce precipitation.
"Around each tiny particle, water starts condensing. When enough droplets accumulate, rainfall occurs," he said.
A cloud-seeding exercise scheduled for Wednesday had to be postponed due to insufficient moisture in the clouds. The IIT-Kanpur director emphasised that the process of cloud seeding is still a cost-effective and scientifically useful method for understanding cloud behaviour and potential rainfall enhancement in urban areas.
(With PTI inputs)
