Key Points
- Delhi conducted its second cloud seeding trial on Tuesday, October 28, 2025, at 1:30 PM and 3:30 PM using a Cessna aircraft from IIT Kanpur
- Eight flares containing silver iodide, each weighing 2-2.5 kg, were dispersed over areas including Burari, Karol Bagh, Mayur Vihar, Khekra, Bhojpur, and Sadakpur
- No rainfall occurred even after four hours, despite officials predicting rain within 15 minutes to 4 hours
- Cloud humidity levels were only 15-20%, far below the 50-60% minimum required for successful cloud seeding
- The India Meteorological Department (IMD) confirmed no forecast of rain-bearing clouds or rainfall over Delhi for the next week
- AAP opposition leader Saurabh Bhardwaj called the experiment a “fraud,” mocking that “even Lord Indra is not supporting the government”
- The Delhi government signed a Rs 3 crore MoU with IIT Kanpur for five trials, now planning 9-10 more attempts in coming days
New Delhi: The Delhi government conducted its second round of cloud seeding trials on Tuesday afternoon in a high-profile attempt to induce artificial rainfall and combat the capital’s severe air pollution crisis. A Cessna aircraft from IIT Kanpur took off from Meerut and entered Delhi airspace around 1:30 PM, releasing chemical compounds over several areas in Northwest Delhi.
Environment Minister Manjinder Singh Sirsa confirmed that the operation covered areas including Khekra, Burari, North Karol Bagh, Mayur Vihar, Sadakpur, and Bhojpur. The aircraft dispensed eight flares containing silver iodide and salt-based compounds, with each flare weighing between 2 and 2.5 kilograms and burning for approximately 2 to 2.5 minutes. The entire seeding process took about 30 minutes during the first sortie.
A second cloud seeding sortie was conducted between 3:30 PM and 4:15 PM over the same areas, with officials hoping the repeated attempts would increase the chances of success. Minister Sirsa stated that according to IIT Kanpur scientists, rainfall could occur anywhere between 15 minutes to four hours after the seeding operation, though it would not be heavy rain due to low humidity in the clouds.
However, sources in the Delhi government confirmed that no rainfall had been recorded in any of the targeted areas even several hours after the trials were completed. The sky remained clear throughout the afternoon and evening, contradicting the optimistic predictions made earlier by government officials.
Unfavorable Weather Conditions Doom Experiment
The primary reason for the failure of the cloud seeding experiment was the extremely low atmospheric moisture levels over Delhi on Tuesday. The clouds over the capital had only 15-20% humidity when the trials were conducted, far below the 50-60% minimum threshold required for effective cloud seeding according to scientific studies.
Weather experts explained that cloud seeding cannot produce rain from scratch but rather accelerates precipitation from already rain-bearing clouds. “Cloud seeding does not produce rain from scratch; we should understand that. It just helps an already rain-bearing cloud to rain faster, or rain sooner,” explained Akshay Deoras, research scientist at the National Centre for Atmospheric Sciences, University of Reading. “It’s not like magic where it will just create rain in any random cloud”.
The India Meteorological Department (IMD) confirmed that there is no forecast of rain-bearing clouds or rainfall over Delhi for at least the next week, casting serious doubt on whether upcoming trials will fare any better. Weather conditions in Delhi have been characterized by clear skies, low humidity, and temperatures 3 degrees below normal for this time of year.
Minister Sirsa acknowledged the challenging conditions, stating in his press statement that “the possibility of rain depends on the amount of moisture in the clouds,” essentially admitting that the atmospheric conditions on Tuesday were not suitable for the experiment. Despite this, the government proceeded with the trials, describing them as “successful” even though no actual rainfall occurred.
Opposition Slams Government Over Failed Trial
The failed cloud seeding experiment immediately drew sharp criticism from opposition parties, particularly the Aam Aadmi Party (AAP), which accused the current Delhi government of conducting a “fraud” in the name of artificial rain. AAP leader Saurabh Bhardwaj posted a video mocking the government’s claims, stating sarcastically that “even Lord Indra is not supporting the government”.
Bhardwaj pointed out that there had been light rainfall on Monday evening, October 27, when some clouds were visible, but by Tuesday afternoon, when the cloud seeding was conducted, even those clouds had disappeared. He questioned why the government chose to proceed with the expensive experiment when atmospheric conditions were clearly unfavorable for success.
The political controversy reflects the broader blame game between AAP, BJP, and Congress over Delhi’s worsening air quality, with Air Quality Index (AQI) levels consistently remaining in the “poor” and “very poor” categories for the past three weeks. After Diwali celebrations, pollution levels spiked dramatically across the National Capital Region, prompting the implementation of Stage 2 of the Graded Response Action Plan (GRAP).
Critics have also questioned the cost-effectiveness of the cloud seeding program, noting that the Delhi government signed a Memorandum of Understanding with IIT Kanpur in September for five trials at a cost of Rs 3 crore (approximately $360,000). Given that the first two trials have both failed to produce any rainfall, opposition leaders are demanding accountability for the expenditure of public funds on what they characterize as an unscientific experiment.
Previous Trial Also Failed
This was not the first unsuccessful cloud seeding attempt in Delhi. The inaugural trial flight was conducted on the night of October 23, 2025, over the Burari area. During that preliminary test, small quantities of silver iodide and sodium chloride compounds were released from the aircraft.
However, that initial attempt also failed to induce any rainfall due to atmospheric moisture levels below 20%, compared to the 50% typically required for cloud seeding to be effective. Despite the clear failure of the first trial due to inadequate moisture, the government proceeded with the second and third attempts on October 28 under similarly unfavorable conditions.
Minister Sirsa had explained before the October 28 trials that the aircraft could only take off if visibility in Kanpur improved to 5,000 meters from the 2,000 meters observed in the early morning. The delayed takeoff pushed the scheduled 12:30 PM start time to approximately 1:30 PM, further reducing the available window for potential rainfall before evening.
Government Plans More Trials Despite Failures
Despite the consecutive failures, Environment Minister Sirsa announced that the Delhi government, in collaboration with IIT Kanpur, plans to conduct 9-10 more cloud seeding trials in the coming days, “whenever weather conditions permit”. He stated that the government wants to “do trials and gather information on what kind of rainfall can occur, and how it can be induced, in every level of humidity”.
Sirsa added that if the trials eventually prove successful, the government will prepare a long-term plan for using cloud seeding in Delhi until February 2026 to reduce air pollution. He expressed hope that “IIT Kanpur’s results will be positive” and that future sorties will continue whenever meteorological conditions allow.
However, weather experts whom ThePrint spoke to said it is highly unlikely that there will be any rain in Delhi after cloud seeding under current atmospheric conditions. The IMD’s forecast predicts partly cloudy skies but no rainfall for at least the next seven days, making immediate success of additional trials improbable.
Scientific Skepticism About Cloud Seeding
The effectiveness of cloud seeding remains a contentious topic within the scientific community, with research yielding varied and often contradictory results. While cloud seeding has been employed by various countries to enhance rainfall for improving air quality or irrigating crops during dry spells, the technique requires very specific atmospheric conditions to work.
Dr. Thara Prabhakaran, a scientist who was involved with cloud seeding experiments conducted by the Indian Institute of Tropical Meteorology in Pune during 2018-2019 in Maharashtra’s Solapur district, emphasized the complexity of the process. “It is not easy to do cloud seeding because there’s inherent variability in each cloud. It depends on the weather, the moisture, the size of the clouds, the origin of the clouds,” she explained.
Prabhakaran noted that it took two years and over 200 different flights and trials to achieve basic understanding and results, with an average increase of only 18% in rainfall due to cloud seeding. “If you’re investing in cloud seeding, you should be able to prove the rainfall is actually because of seeding, robustly with experiments. It can’t happen with one or two trials,” she emphasized.
Studies from China, Australia, and the United Arab Emirates have shown that cloud seeding depends heavily on meteorological conditions such as wind speed, cloud type, humidity levels, and the presence of existing rain-bearing clouds. Research has also indicated that in cases where favorable conditions are not present, cloud seeding can potentially lead to increased PM2.5 particulate matter levels, potentially worsening air quality rather than improving it.
Environmentalists Call It a Short-Term Fix
Environmental advocates have raised alarms over Delhi’s cloud-seeding experiment, dismissing it as merely a stopgap solution that fails to address the root causes of the city’s worsening pollution crisis. Critics emphasize that while artificial rain may temporarily wash pollutants from the atmosphere, it does nothing to prevent the continuous generation of pollution from vehicular emissions, construction dust, industrial activities, and crop residue burning.
Manindra Agrawal, a professor involved in pollution research, stated that artificial rain triggered by cloud seeding can potentially bring down pollution levels by as much as 50%, but the effect is temporary and may need to be repeated frequently. Given Delhi’s chronic pollution problem that persists throughout the winter months, relying on cloud seeding would require continuous operations at enormous cost.
Environmentalists argue that the government should instead focus on long-term structural solutions such as stricter enforcement of emission norms, expansion of public transportation, transition to cleaner fuels, implementation of dust control measures at construction sites, and comprehensive management of agricultural stubble burning in neighboring states.
Delhi’s Air Quality Remains Critical
On Tuesday afternoon, when the cloud seeding trials were conducted, Delhi’s air quality remained categorized as “very poor,” with the overall AQI registering 304 according to the Central Pollution Control Board. The CPCB classifies air quality from 0 to 50 as “good,” meaning Delhi’s pollution levels were more than six times the healthy threshold.
Every winter, Delhi and its neighboring regions experience severe pollution as cold, dense air traps dust from construction sites, emissions from millions of vehicles, and smoke from agricultural burning in Punjab and Haryana. This toxic cocktail leaves many of Delhi’s 20 million residents grappling with respiratory issues, eye irritation, and other health problems.
Stage 2 of the Graded Response Action Plan (GRAP) continues to remain in force across the National Capital Region, implementing restrictions on construction activities, industrial operations, and vehicular movement to curb pollution levels. However, these measures have proven insufficient to bring air quality into acceptable ranges, prompting the government to experiment with more unconventional approaches like cloud seeding.
What Is Cloud Seeding?
Cloud seeding is a weather modification technique that involves introducing chemicals such as silver iodide (AgI), salt particles, or sodium chloride into clouds to trigger or enhance precipitation. These particles act as condensation nuclei, allowing moisture in the atmosphere to condense into ice crystals that eventually form larger water droplets, which can fall as rain.
The method works by dispersing these seeding agents from aircraft flying through or above clouds. As the flares burn, they release the chemical compounds into the cloud structure, theoretically accelerating the natural rain formation process. When successful, cloud seeding can help increase rainfall in drought-affected areas, reduce pollution by washing airborne pollutants from the atmosphere, and improve overall air quality.
However, the technique requires suitable cloud conditions with sufficient moisture content—typically at least 50-60% humidity—along with appropriate cloud types, favorable wind patterns, and adequate atmospheric instability to be effective. In the absence of these conditions, cloud seeding becomes ineffective and cannot produce rainfall regardless of the quantity of chemicals dispersed.
This marks the first time that cloud seeding has been attempted in Delhi as a pollution control measure, though the technique has been used in other parts of India and around the world for various purposes, including agricultural water management and air quality improvement. The Delhi government’s experiment represents a controversial and expensive attempt to address an environmental crisis that most experts believe requires comprehensive long-term policy interventions rather than technological quick fixes.
