Indian authorities conducted a cloud-seeding trial over New Delhi on Tuesday, 28 October 2025, aiming to induce rainfall and flush particulate pollution from the capital’s air.
The operation, undertaken as air quality monitors placed the city in the “very poor” band, involved an aircraft deploying hygroscopic particles into suitable cloud formations above parts of the metropolis. Officials described the exercise as experimental and said further sorties were envisaged in the coming days if atmospheric conditions allowed. AP News+1
Manjinder Singh Sirsa, Delhi’s environment minister, said the trial was organised with the Indian Institute of Technology Kanpur (IIT-Kanpur). According to statements reported by domestic media, aircraft departed from Kanpur and, in a second instance, from Meerut to seed clouds over outer Delhi neighbourhoods. Authorities indicated they hoped for short, localised showers later on Tuesday to help reduce suspended particulate matter. Reuters+2Hindustan Times+2
Cloud seeding is a weather-modification technique that disperses small particles—often silver iodide or salt—into clouds to encourage droplet formation and precipitation. It has been used periodically in arid parts of the western United States and the United Arab Emirates, usually to augment rainfall rather than as an air-quality intervention. Scientists note that results vary and depend on cloud type, moisture, wind and temperature; evidence for consistent pollution reduction is limited. AP News
The decision to proceed followed a week of deteriorating air in and around the National Capital Territory. In the aftermath of Diwali festivities, New Delhi’s pollution spiked to “hazardous” levels on 21 October, with hourly readings reported by IQAir ranking the city among the worst globally. Authorities subsequently tightened restrictions, including curbs on construction activity and limits on diesel generator use, and deployed water sprinklers and so-called anti-smog guns on arterial roads. Forecasts issued last week suggested only modest short-term improvement without a change in weather patterns. Reuters
On Tuesday, independent and official monitors still placed New Delhi’s air in the “very poor” category. The wider region—home to more than 30 million residents—regularly endures severe winter smog as cooler temperatures trap emissions close to the ground. The seasonal build-up is driven by a mix of vehicle exhaust, industrial activity, dust from construction, and smoke from the post-harvest burning of crop residue in surrounding states. Annual assessments by IQAir have repeatedly listed Indian cities among the world’s most polluted, with Delhi ranked the most polluted capital in 2025 mid-year reporting. AP News+2iqair.com+2
Researchers cautioned that cloud seeding offers, at best, temporary relief. Krishna Achuta Rao, professor at the Centre for Atmospheric Sciences at the Indian Institute of Technology, New Delhi, said any pollution reduction from induced rainfall is likely to be short-lived and contingent on favourable meteorology. Once precipitation stops and emissions continue, he noted, concentrations can return to prior levels within days. He argued that sustained improvement depends on stricter controls across sources, including industry, transport and construction. AP News
Officials in Delhi have explored artificial rain intermittently over the past decade, but attempts have often been delayed by unsuitable cloud conditions, regulatory permissions, or procurement. Tuesday’s sorties were billed as trials to assess feasibility, operational logistics and measurable impact under current synoptic conditions. The government signalled that results—such as changes in PM2.5 concentrations in targeted zones compared with control areas—would inform whether to scale up operations during peak smog episodes. Reuters
International experience with weather modification remains mixed. Programmes in the western United States and parts of the Middle East have focused primarily on snowpack enhancement and water-resource gains rather than air-quality outcomes. Peer-reviewed studies have documented precipitation increases under some conditions, but results are highly variable and context-dependent. Public health specialists typically regard emission abatement—fuel standards, clean power, dust control, and agricultural residue management—as the core of long-term urban air-quality strategy, with rainfall events providing episodic dilution rather than structural change. AP News
For Delhi, the immediate question is whether targeted showers can meaningfully compress pollutant peaks during an early winter inversion. Authorities said further flights would proceed subject to cloud availability and clearances from aviation authorities. Data from ground stations across the capital and satellite observations will likely be scrutinised in the coming days for evidence of localised reductions attributable to the operation, beyond weather-driven fluctuations. Reuters
New Delhi’s air remains a recurrent policy test. While Tuesday’s effort represents an escalation in tactical responses, the government’s broader programme—ranging from vehicle emission norms to restrictions on construction dust and seasonal curbs on generators—will continue to be assessed against the city’s pollution trajectory through November and December, when conditions typically worsen. Independent monitoring organisations have urged transparent reporting of trial parameters and outcomes to inform any further use of cloud seeding as an air-quality measure. Reuters+1
