The 1966 Pacific typhoon season has no official bounds, but most tropical cyclones tend to form in the northwestern Pacific Ocean between June and December. These dates conventionally delimit the period of each year when most tropical cyclones form in the northwestern Pacific Ocean.
115 mph Typhoon Irma hit the eastern Samar on May 15. It weakened over the island, but re-intensified rapidly to a 140 mph typhoon in the Sibuyan Sea before hitting Mindoro on the 17th. After weakening to a tropical storm, Irma turned northward to hit western Luzon as a 95 mph typhoon on the 19th. It accelerated to the northeast, and became extratropical on the 22nd. In the Philippines Irma killed 82 people.
Typhoon Kit, which formed on June 22, rapidly intensified on the 25th and 26th to a 195 mph Super Typhoon. Such intensity is questionable, because Reconnaissance Aircraft was in its infancy, but Kit was likely a powerful typhoon. It weakened as it moved northward, and passed just east of Honshū, Japan on the 28th as a minimal typhoon. There Kit killed 64 people, with 19 missing.
Super Typhoon Alice developed in the Western Pacific from a tropical wave on August 25. It moved to the north, looped to the west, and steadily strengthened to a peak of 150 mph. Alice continued to the west, hit eastern China on September 3, and dissipated the next day. Damage reports are not available.
Typhoon Cora, which began its life on August 30, attained peak winds of 175 mph on September 5th. It passed near Okinawa, causing major damage to the infrastructure on the island, but no loss of life. Cora continued to the northwest, hit northeastern China as a super typhoon on the 7th, and turned northeast to become extratropical near South Korea on the 9th.
On September 24, two tropical systems made landfall on Japan. Helen struck the southwestern part of the archipelago as a minimal tropical storm, and 115 mph Typhoon Ida hit eastern Japan at the same time. The two storms' heavy rain and flooding left 300 people dead or missing, with over 700 missing.