Artificial Rain in Delhi: Understand Science Behind Cloud Seeding and Its Role in Reducing Air Pollution

As Delhi faces one of its most severe air quality crises in recent years, the government has sought scientific intervention. The Delhi government, in partnership with IIT Kanpur, has initiated cloud seeding trials to induce artificial rain in the capital. The primary goal is to alleviate the heavy smog and fine dust particles that plague Delhi NCR each winter.

For students, this endeavor transcends a mere weather experiment; it serves as a practical display of applied science and environmental technology. Grasping the scientific principles of cloud seeding allows students to observe firsthand how scientific innovation can address real-world challenges such as air pollution.

What Is Cloud Seeding and How Does It Work?

Cloud seeding is a scientific process used to induce artificial rain by dispersing certain substances into the atmosphere to encourage cloud condensation and precipitation.

Here’s how it works:

- Aircraft spray chemicals like silver iodide, rock salt, or dry ice into the clouds.

- These substances act as condensation nuclei, helping water vapour gather and form larger droplets.

- Once heavy enough, the droplets fall as rain, which helps clear out pollutants and dust from the air.

Science Concept for Students:

- This process uses principles of condensation and nucleation studied in Physics and Geography.

- It doesn’t create clouds but enhances rainfall in existing ones under the right conditions.

Delhi’s Artificial Rain Project 2025: Latest Updates

The Delhi government, supported by IIT Kanpur, has launched a pilot cloud seeding program to reduce pollution. This marks the first-ever large-scale artificial rain project in India’s capital.

Project Highlights:

The table below summarizes the key features of the project:

Recent Developments (October 2025):

• Trials were conducted on October 28, 2025, over Delhi NCR.
• However, the first seeding attempt failed to produce significant rainfall due to low cloud moisture (below 20%).
• Experts stated that humidity of at least 50–60% is required for successful artificial rain.
• The Delhi government plans 9–10 more trials, depending on weather conditions.

Why Artificial Rain Is Needed in Delhi

Every winter, Delhi’s Air Quality Index (AQI) slips into the “severe” category due to multiple factors like vehicle emissions, industrial activity, and stubble burning in Punjab and Haryana. The dense smog causes health problems, reduces visibility, and disrupts daily life.

Why cloud seeding seems like a solution:

• Artificial rain can temporarily settle dust and particulate matter from the air.
• It helps reduce PM2.5 concentration and improve visibility.
• It’s seen as a quick emergency measure when pollution spikes.
• However, experts emphasize that cloud seeding is not a long-term solution — it’s a temporary relief mechanism that depends on favourable weather.

Scientific Benefits and Learning Value

Cloud seeding combines meteorology, chemistry, and environmental science, making it an exciting study topic for students.

Educational Insights:

1. Shows how science and technology work together to solve environmental issues.
2. Encourages critical thinking about weather modification and climate engineering.
3. Helps students connect classroom topics like precipitation, aerosols, and air quality to real-world challenges.

Potential Environmental Benefits:

• Artificial rain can temporarily lower pollution levels by 30–50%.
• It can clean the air, wash away particulate matter, and cool surface temperatures.
• If successful, Delhi’s project could become a model for other polluted cities in India.

Challenges and Limitations of Cloud Seeding

While cloud seeding offers scientific promise, its success rate remains uncertain. The process depends entirely on the presence of moisture-laden clouds, which are often missing during Delhi’s smog season.

Major Limitations:

• Weather-dependent: Works only when the right cloud conditions exist.
• High cost: Each trial costs lakhs of rupees with unpredictable results.
• Short-term relief: Rain washes away pollutants temporarily but doesn’t stop emissions.
• Environmental impact: Overuse of chemicals like silver iodide may have long-term ecological effects (though minimal in small quantities).
• Experts suggest cloud seeding should be combined with long-term solutions like emission control, clean fuel use, and green mobility for sustainable results.

Student Takeaways – Science in Action

For students, the artificial rain experiment in Delhi is a real-world case study of how science can address complex urban problems.

Key Learnings for Students:

1. Understand the science behind precipitation and condensation.

2. Explore the intersection of meteorology, technology, and environmental policy.

3. Analyze the advantages and limitations of technological interventions in pollution control.

4. Encourage curiosity about environmental innovation and research in India.

Cloud-seeding activity in Delhi put on hold due to low moisture, says IIT Kanpur

• Cloud-seeding for Wednesday in Delhi postponed due to insufficient cloud moisture.

• IIT Kanpur noted the process's dependence on favorable atmospheric conditions; another attempt is planned soon.

• Tuesday's trial, despite low moisture, offered valuable insights.

• Monitoring showed a 6-10% reduction in PM2.5 and PM10, indicating improved air quality even with limited moisture.

• These observations will help plan future operations and identify optimal conditions.

• IIT Kanpur is dedicated to advancing this research for environmental improvement in the NCR.

• IIT Kanpur Director Manindra Agrawal clarified cloud seeding is an emergency, last-resort measure, not a permanent solution.

• The team plans fresh attempts in the coming days.

• The IIT Kanpur-led team used a mixture of 20% silver iodide, rock salt, and common salt; 14 flares were fired on Tuesday.

• Agrawal emphasized that the permanent solution is to control pollution sources, and cloud seeding is a temporary relief tool.

A Blend of Science and Sustainability

Delhi’s cloud seeding project highlights the growing role of science and innovation in tackling environmental issues. While the first attempts may not have succeeded, the initiative has sparked valuable discussions about how technology can be used to protect public health.

For students, this is a lesson in applied science, problem-solving, and critical thinking. Artificial rain may not be a permanent fix, but it represents a forward-thinking approach to one of India’s biggest urban challenges — air pollution.