Cloud seeding involves using aircraft or drones to add to clouds particles of silver iodide, which have a structure similar to ice. Water droplets cluster around the particles, modifying the structure of the clouds and increasing the chance of precipitation. Months of unpredictable weather over India's capital had put the BJP's cloud-seeding plans on pause. But days after Delhi's air quality once again fell into the hazardous range after Diwali festival, and a thick brown haze settled over the city, the government said the scheme would finally be rolled out.