Abstract: A spray nozzle in which a plurality of streams of water under pressure are initially broken up mechanically within a chamber by impingement against a deflector therein and by the shearing action of its knife edge, and are then atomized and initially cooled within the chamber by jets of expanding compressed air, the cooled air and atomized water mixture then being discharged from an annular orifice in the form of a hollow cone spray in which the atomized water is further cooled by reason of the temperature drop in the discharged air because of its expansion upon discharge. This results in the formation of snow flakes where the ambient atmospheric temperature is sufficiently low to effect freezing of the discharged atomized water.