Delhi Plans a Fresh Cloud Seeding Attempt to Fight Air Pollution: How Artificial Rain Works
Delhi is set to make another attempt at cloud seeding (adding particles to clouds so that they give rain) on 10 and 11 November 2026, hoping rain will wash pollutants out of its very polluted air.
The attempt is a joint effort of Delhi International Airport Ltd (DIAL), the Delhi government and IIT Kanpur.
A specialised Beechcraft 200 aircraft of Kyathi Climate, a Bengaluru-based weather-modification company, will carry out the seeding whenever suitable clouds form.
This aircraft can fly up to about 25,000 feet. The aircraft used in Delhi's earlier attempt could reach only about 10,000 feet.
Delhi's earlier cloud seeding trials in October 2025 failed to produce useful rain because the air had too little moisture.
A fresh western disturbance (a winter weather system from the west) is expected to bring rain to the plains of north-west India later this week.
Cloud Seeding: How Artificial Rain Is Made
Cloud seeding is a way of trying to get more rain or snow out of a cloud by adding tiny particles to it. These particles, usually silver iodide or common salts, act as "seeds" around which water collects into drops or ice crystals big enough to fall. Cloud seeding cannot create clouds from clear sky. It can only help a suitable cloud that already has enough moisture to give a little more rain than it would on its own.
Delhi is trying cloud seeding again, this time with a Beechcraft 200 aircraft that can reach about 25,000 feet, much higher than the plane used in 2025. Height helps the aircraft reach the colder parts of clouds where silver iodide works. But the core limits explained here still apply: seeding needs moist, suitable clouds, and any rain gives only short relief from pollution. Timing the attempt with an approaching western disturbance raises the chance that suitable clouds will be present.
Western Disturbances: How They Shape India's Winter Weather
A western disturbance (WD) is a weather system that forms far to the west of India, mostly over the Mediterranean Sea, and travels east to north India, bringing winter rain to the plains and snow to the Himalayas. It is carried along by a fast, high-level wind called the subtropical westerly jet stream. Western disturbances are the main reason north-west India gets rain in winter, when the monsoon is long over.
Delhi has timed its cloud seeding attempt as a fresh western disturbance approaches north-west India. A WD brings moist air and clouds to a region that is otherwise dry in winter, which is exactly what seeding needs. If the WD itself brings rain and strong winds, it can clean Delhi's air for a few days even without seeding.
Air Quality Index (AQI) Framework
The Air Quality Index (AQI) is a single number, from 0 to 500, that tells people how clean or polluted the air is on a given day. Instead of giving many separate readings for different pollutants, it combines them into one easy figure with a colour and a name, such as "Good" or "Severe". The higher the number, the worse the air.
Delhi's air is in the very poor to severe AQI range, which is why authorities are trying cloud seeding. Rain from seeding or from a western disturbance can bring the AQI down, but only until the pollution builds up again.
- Planned cloud seeding: 10-11 November 2026, over Delhi
- Partners: Delhi International Airport Ltd (DIAL), Delhi government, IIT Kanpur
- Aircraft: Beechcraft 200 of Kyathi Climate (Bengaluru); can reach about 25,000 feet (earlier aircraft: about 10,000 feet)
- Earlier Delhi trials: October 2025; failed because of low cloud moisture (about 10-15%)
- CAIPEEX-IV (Solapur, 2018-19): about 18% average rainfall increase from hygroscopic seeding
- Silver iodide works best in clouds colder than about -5°C
- Western disturbances: originate mainly over the Mediterranean; carried by the subtropical westerly jet; bring winter rain to north-west India
- AQI scale: 0-500, 6 categories, 8 pollutants; "Severe" = 401-500