Saturn's atmospheric constituents are, in order by mass, hydrogen (88 percent) and helium (11 percent); and traces of methane, ammonia, ammonia crystals, and such other gases as ethane, acetylene, and phosphine comprise the remainder. Voyager images showed whirls and eddies of clouds occurring deep in a haze that is much thicker than that of Jupiter because of Saturn's lower temperature. The temperatures of Saturn's cloud tops are close to -176° C, about 27° C lower than such locations on Jupiter.

Based on the movements of Saturnian storm clouds, the period of rotation of the atmosphere near the equator is about 10 hr 11 min. Radio emissions that have been detected coming from the body of the planet indicate that the body of Saturn and its magnetosphere rotate with a period of 10 hr 39 min 25 sec. The approximately 28.5-min difference between these two times indicates that Saturnian equatorial winds have velocities close to 1700 km/h.