The current work is devoted to investigation of self*organization phenomena in magnetics under action of magnetic field, that appears as formation of dynamic domain structures with complex spatiotemporal organization. Presented results of investigation of dynamic spiral magnetic domains were obtained on epitaxial (111) iron garnet film placed in harmonic magnetic field of sound frequencies oriented perpendicularly to the sample surface. High*speed video recording and program recognition of dynamic domain structure allowed to obtain distributions of spiral dynamic domains radii through temperature range 77-350 K and establish character of their change.