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How fast are the winds on Neptune?

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Clouds in Neptune's atmosphere — Neptune A photograph of clouds in Neptune's atmosphere, taken by Voyager 2 in August 1989. The view is from below the planet's equator, and north is up. The Great Dark Spot (center left) is 13,000 km (8,100 miles)—about the diameter of Earth—in its longer dimension. Accompanying it are bright, wispy clouds thought to comprise methane ice crystals. At higher southern latitudes lies a smaller, eye-shaped dark spot with a light core (bottom left). Just above that spot is a bright cloud dubbed Scooter. Each of these cloud features was seen to travel eastward but at a different rate, the Great Dark Spot moving the slowest.

Neptune exhibits the fastest winds observed on any planet in the solar system. These winds are constrained to blow in a zonal flow, generally moving east-west along lines of constant latitude.12

Wind speeds on the planet vary significantly by location:

Easterly (prograde) winds: Near latitude 70° S, wind speeds reach approximately 100 meters per second (360 km, or 220 miles, per hour).2
Westerly (retrograde) winds: Near latitude 20° S, wind speeds can reach as high as 700 meters per second (2,520 km, or 1,570 miles, per hour).2

These high-velocity winds, combined with internal heat escaping from the planet's interior, are believed to contribute to the significant atmospheric turbulence observed on Neptune.21