Delhi's ambitious plan to induce artificial rain and combat its persistent air pollution is currently facing an unexpected hurdle: a lack of clouds. The cloud seeding project, initially slated for July 2025, has been postponed multiple times due to various reasons, including the monsoon season, shifting weather patterns, and now, the absence of suitable cloud cover.
Delhi Environment Minister Manjinder Singh Sirsa has stated that the capital is ready for the artificial rain experiment but is awaiting the right conditions. According to the India Meteorological Department (IMD), a window for the experiment is not expected to open until October 25. "The day we get suitable clouds, we will conduct the trial immediately, as all preparations — from permissions to flight arrangements — are already in place," Sirsa told PTI.
The Delhi government's cloud seeding project, a ₹3.21 crore initiative, is a collaborative effort with the Indian Institute of Technology (IIT) Kanpur. IIT Kanpur has modified a Cessna-206H aircraft for the project. The project aims to explore whether artificial rain can be a viable solution to tackle pollution in winter. Funds have already been transferred to IIT Kanpur, which will deploy its aircraft for the operation. The Directorate General of Civil Aviation (DGCA) has cleared the project, permitting trials between October 1 and November 30.
Cloud seeding involves dispersing substances such as silver iodide into clouds to enhance their ability to produce rain. Nimbostratus clouds, typically located between 500m and 6,000m above ground, are considered ideal for seeding, but they must contain at least 50% moisture. Currently, Delhi's skies lack sufficient moisture and cloud density.
Four days of trial flights have been conducted over northwest Delhi, the area chosen for the pilot project. The pilots have completed training and are familiar with the flight path. The aircraft is stationed in Meerut, fully equipped for the cloud seeding process.
The government hopes that artificial rain can help wash out airborne pollutants, providing temporary relief to citizens. Experts suggest that rainfall could improve the Air Quality Index (AQI) by 50-80 points, potentially shifting air quality from "very poor" to "poor," or from "poor" to "moderate". However, the impact depends on wind speed, the area of influence, and the intensity of the rain. Light rain or drizzle is unlikely to make a significant difference; sustained and strong showers are needed for a "washout effect".
While the initiative has generated optimism, some experts caution that cloud seeding's effectiveness is difficult to quantify. The Centre for Science and Environment noted that Delhi was the most polluted megacity in the country during the 2024-25 winter, with an average PM2.5 concentration of 175 micrograms per cubic meter. Concerns also exist regarding the potential environmental impacts of cloud seeding, such as chemical residue and the limited duration of any improvement in air quality.
Despite the delays and uncertainties, the Delhi government remains committed to exploring innovative solutions to combat air pollution. The cloud seeding project represents a significant step towards technological intervention, with authorities closely monitoring weather conditions and awaiting the opportune moment to initiate the trial.
