Typhoon Marge originated as a tropical storm southeast of Guam on August 10. Tracking towards the northwest, the strengthening system passed just south of the island the following day as a typhoon. On August 13, the storm began taking a more northwesterly path as it continued to intensify, reaching its peak intensity two days with maximum winds estimated at 185 km/h (115 mph) and a remarkably low pressure of 886 mbar (hPa; 26.16 inHg). Fluctuating in strength over the following days, Marge passed over the Amami Islands on August 18 before a more steadily weakening trend took hold as the typhoon moved into the East China Sea. The storm passed just offshore Shanghai before curving sharply towards the northeast into the Yellow Sea on August 21. Marge weakened to a tropical storm the next day after spending 11 continuous days as a typhoon. The cyclone made landfall near Boryeong, South Korea on August 23 and accelerated northeastwards across the Korean peninsula, transitioning into an extratropical cyclone over far-northeastern Manchuria before dissipating after August 24.