[Animats]

Santa Clara County had an active cloud-seeding program from 1954 through 1994.[1] Santa Clara County used to be a major agricultural area. The goal is not to create rain, but to move it. Get the clouds to dump over the agricultural areas instead of the inland mountains. It worked, a little. But there was a concern that it was making wildfires worse, by doing what it was intended to do and thus making the inland forests more dry.

[1] https://s3.us-west-1.amazonaws.com/valleywater.org.us-west-1...

[dangero]

To my point, liability concerns are listed on that pdf as a reason why Santa Clara County stopped.

Cloud seeding can definitely increase rain over California even by your logic. Clouds don't respect state boundaries.