Efforts to induce artificial rain through cloud seeding over parts of Delhi on Tuesday were “not completely successful,” as the clouds had very low moisture content, according to IIT Kanpur Director Manindra Agarwal. The experiment, carried out jointly by IIT Kanpur and the Delhi government to combat worsening pollution, yielded minimal rainfall and only a modest reduction in particulate matter levels.
“There hasn’t been any rain so far, so in that sense, it was not completely successful, Unfortunately, the clouds today did not have high moisture only around 15–20%. The chances of causing rain with such low moisture are limited. But the trial gave our team more confidence to continue testing,” he said.
During Tuesday experiment, the team fired 14 flares containing a mixture of 20% silver iodide, rock salt, and common salt from aircraft operating out of Uttar Pradesh. While some forecasts had predicted rainfall, the team found that the cloud cover over Delhi lacked sufficient humidity to trigger precipitation.
Agarwal confirmed that two more flights are planned for Wednesday, adding that the process will continue whenever suitable cloud cover is available.
Clarifying that cloud seeding is not a long-term solution to Delhi pollution crisis, Agarwal called it an “SOS solution.” “When pollution levels reach a crisis point, this can be one of the temporary methods to bring some relief. But the permanent solution lies in controlling emissions and addressing the sources of pollution,” he said. “Ideally, we should reach a point where there’s no need for cloud seeding because there’s no pollution to begin with.”
The IIT director also acknowledged the high operational costs due to the flights being conducted from Uttar Pradesh but said those could be reduced with better logistics.
The Delhi government, in its report following the experiment, claimed a measurable improvement in air quality in areas where the seeding was conducted. It noted light precipitation 0.1 mm of rain in Noida and 0.2 mm in Greater Noida around 4 p.m.
According to government data, the average PM2.5 levels dropped slightly after the first round of cloud seeding: from 221 to 207 in Mayur Vihar, from 230 to 206 in Karol Bagh, and from 229 to 203 in Burari. PM10 levels also fell from 207 to 177, 206 to 163, and 209 to 177 in the same areas.
While the impact was limited, officials and experts agree that even a brief reduction in pollutant levels can bring temporary relief to residents. More trials are expected to continue through the week depending on weather conditions.