​TYPHOON (probably from the Arabic and Hindustani tufān, a tempest, which is perhaps derived from Typhon, q.v.: the Chinese t'ai fung, strong wind, is not used in application to typhoons), the name given to a heavy cyclonic storm in the seas fringing the eastern coast of Asia from Japan to the Philippine Islands. Typhoons generally occur in a series during the August, September and October, the season when the belt of equatorial calms in the Pacific Ocean reaches its northerly extension.