The 2004 Pacific typhoon season was an extremely active season that featured the second-highest ACE ever recorded in a single season, second only to 1997, which featured 29 named storms, nineteen typhoons, and six super typhoons. It was an event in the annual cycle of tropical cyclone formation, in which tropical cyclones form in the western Pacific Ocean. The season ran throughout 2004, though most tropical cyclones typically develop between May and October. The season's first named storm and also the first typhoon, Sudal, developed on April 4, later was reached typhoon status two days later, and became the first super typhoon of the year three days later. The season's last named storm, Noru, dissipated on December 21.

Typhoon Sudal, known in the Philippines as Typhoon Cosme, was the strongest typhoon to strike the island of Yap in the Federated States of Micronesia (FSM) in about 50 years. Yap is one of the four administrative divisions of the FSM. The entire island, only 17 km (11 mi) in length, experienced typhoon force winds, and 90% of the structures were damaged or destroyed. Damage was most severe in southeastern Yap, where the eyewall struck and winds exceeded 185 km/h (115 mph), but the center of the typhoon passed south of the island.