CloudSeeding

Cloud seeding is a type of weather modification that aims to change the amount or type of precipitation, mitigate hail or disperse fog. The usual objective is to increase rain or snow, either for its own sake or to prevent precipitation from occurring in days afterward.

From 1967 to 1972, the U.S. military's Operation Popeye cloud-seeded silver iodide to extend the monsoon season over North Vietnam, specifically the Ho Chi Minh Trail. The operation extended the monsoon period an average of 30 to 45 days in the targeted areas. The 54th Weather Reconnaissance Squadron carried out the operation to "make mud, not war".

Conspiracy Theories

Cloud seeding has been the focus of many theories based on the belief that governments manipulate the weather in order to control various conditions during Operation Popeye, including global warming, populations, military weapons testing, public health, and flooding.

A 2016 classified ad placed by Los Angeles County's Department of Public Works in the Pasadena Star News sparked claims that widespread weather modification was being confirmed. The department followed up with a clarification that it was only describing cloud seeding, used as an anti-drought measure intermittently for more than half a century in Los Angeles.