Rainmaking

rainmaking, any process of increasing the amount of precipitation discharged from a cloud. Primitive methods, such as rain dances or the throwing of pebbles into water, fail to produce rain. However, modern techniques of cloud seeding, such as efforts to coax precipitation from supercooled clouds (clouds containing liquid water droplets at temperatures below 0 °C [32 °F]) with frozen carbon dioxide or silver iodide, as well as from warmer clouds (clouds containing liquid water droplets at temperatures above 0 °C) with calcium chloride, offer some possibility of increasing rainfall amounts.