Government-backed researchers in China recently conducted a drone-based weather experiment over Xinjiang that led to a measurable increase in rainfall. The trial, overseen by Li Bin of the China Meteorological Administration, covered over 8 000 km2 (3 089 mi2) and pushed precipitation levels up by more than 4% within a single day.
The operation generated over 70 000 m3 (2.4 million ft3) of additional rainfall using just 1 kg (2.2 pounds) of silver iodide. This compound, commonly used in cloud seeding, is six times denser than water. The total amount used was small enough to fit into a standard travel mug.
These findings were a part of a paper published in the Chinese-language journal of Desert and Oasis Meteorology on April 10, 2025. China’s laboratory of cloud-precipitation physics and weather modification in Beijing was the conducting body. Guizhou, Shanghai, Gansu, and Sichuan were also subjected to a similar experiment.
Mathematically assessing the impact of drone-driven weather modification in Xinjiang
As a part of this study, on July 9, 2023, two models of medium-sized drones flew to an altitude of 5 500 m (18 000 feet) over the Bayanbulak Grasslands. During four separate flights, the drones released silver iodide wrapped in flame bars, which were dispersed into the atmosphere as smoke. Each flight utilized two flame bars, with each bar containing 125 grams (0.2 pounds) of silver iodide. The particles were released at a rate of 0.28 g/s.
Lin elucidated in the paper that drone systems offer lower safety risks, better maneuverability, precise control, and wide coverage. He emphasized that these advantages make drones suitable for all-weather, year-round, three-dimensional, and large-scale rain or snow enhancement operations.
To solidify its concreteness, Lin and his team sought to address key uncertainties about cloud-seeding operations. These included how to determine if they genuinely increased or accidentally reduced precipitation, what metrics should be used to measure the water volume changes, and the overall impact when applied over a full year. These questions have been raised by both the government and the public. To ensure the accuracy of their findings, the team worked with Xinjiang’s Weather Modification Office and employed three different methods to validate the results.
Data from raindrop spectrometers revealed a noticeable increase in droplet size, from 0.46 mm (0.2 inches) to 3.22 mm (0.12 inches), after the seeding took place. Satellite observations also showed a drop in cloud-top temperatures by as much as 10°C (50°F). Along with that, the vertical cloud development reached nearly 3 km (1.8 miles). These physical indicators pointed to a clear impact from the operation.
Using half a century of regional climate records, the team estimated that the operation added roughly 78 200 m³ (2.7 million ft3) of rainfall. In totality, this reflected a 3.8% increase. Simulations run on a supercomputer projected a similar outcome, with an estimated rise of 73 800 m³ (2.6 million ft3) or a 4.3% boost. These figures closely matched the measurements recorded on the ground. Researchers also noted that the results of weather modification changed widely based on location and timing.
The potential of cloud-seeding to mitigate Xinjiang’s environmental threats
Researchers plan to expand cloud-seeding trials with more detailed simulations to better understand how factors like timing, altitude, and dosage influence rainfall outcomes.
This work is particularly important in Xinjiang, where the climate catastrophes such as desertification and melting glaciers actively threaten water supplies for millions.
