Typhoon, (from the Chinese taifung, great wind), a severe tropical cyclonic storm occurring in the western Pacific Ocean. It is identical to the hurricane of the Atlantic, with winds up to 150 or even 200 miles per hour (240 or 320 kmh). Although typhoons occur most frequently during the warmest months, they have been recorded during every month of the year. Like hurricanes, typhoons originate only over warm seas, principally between the latitudes of 5 and 20 North. Many begin in the area of the Caroline Islands, but others originate as far west as the South China Sea.

The exact course of a typhoon is unpredictable, but most follow a general pattern. After moving slowly westward in their early stages, they then curve northward and begin to move faster. Heavy damage from high winds and flooding is the usual result when a typhoon passes over land. Most frequently affected by typhoons are the Mariana Islands, the Philippines, southeastern China, and Japan.