Namtheun was a TS tropical cyclone that formed in the East China Sea in 2021. The storm reached maximum sustained winds of 93 km/h (50 kt) with a minimum central pressure of 996 hPa. Tracking across the East China Seain the Western Pacific basin (, it potentially affected Japan, Korea, Taiwan and eastern China. The storm traveled from approximately 16.2°151.8° to 40.7°169.4°, crossing a range of 25 latitude and 18 longitude.