Utah has experimented with cloud seeding for decades, using ground devices and airplanes to disperse silver iodide and liquid propane to pad moisture statistics in one of the nation’s driest states.

Cloud-seeding is a technique used to modify weather by releasing silver iodide (AgI) into the atmosphere to facilitate the formation of ice crystals, enhancing the cloud's ability to generate rain.

It is now five years since dry ice was first used to make rain. An account of the present state of the technique, with special reference to the sowing of silver iodide for large-scale effects ...