China’s come a long way since 1958, when Russia brought cloud-seeding to the Middle Kingdom. It’s now the most trigger-happy cloud-seeder in the world. In 2011, China spent $150 million on a single regional artificial rain program; it’s unclear how much other local governments spend.
The US, by comparison (according to this article), spends around $15 million a year. It now creates 50 billion tonnes (55 billion tons) of artificial rain a year. That compares with an average of 36 billion tonnes a year (40 billion tons) from 1999 to 2006.