Typhoon Ida, known in

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

as Makurazaki Typhoon ( 枕崎台風), was a powerful and very deadly

typhoon A typhoon is a tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere and which produces sustained hurricane-force winds of at least . This region is referred to as the Northwestern Pacific Basin, accounting for a ...

that formed over the western Pacific Ocean and struck Japan in September 1945, shortly after the Japanese surrender in World War II, causing over 2,000 deaths. The storm struck parts of

Kyushu is the third-largest island of Japan's Japanese archipelago, four main islands and the most southerly of the four largest islands (i.e. excluding Okinawa Island, Okinawa and the other Ryukyu Islands, Ryukyu (''Nansei'') Ryukyu Islands, Islands ...

and

Ryukyu The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Geography of Taiwan, Taiwan: the Ryukyu Islands are divided into the Satsunan Islands (Ōsumi Islands, Ōsumi, Tokara Islands, Tokara and A ...

which had already been ravaged by the war and compounded the effects of the atomic bombing of Hiroshima, which had occurred only one month prior, resulting in further devastation to the already destroyed city. The typhoon likely had much higher wind speeds than were recorded at the time, with current estimates of the storm's minimum pressure as low as 917 millibars, though meteorologists are uncertain of the storm's true intensity. The typhoon remains one of the deadliest in Japanese history and is one of only a few storms to be known by a separate name in Japanese.

Meteorological history

A tropical depression formed in the West Pacific on September 10 and intensified before being designated as Typhoon Ida. Ida continued to slowly move westwards, and after beginning to curve north rapidly intensified into a powerful typhoon. The storm made landfall near Makurazaki in

Kagoshima Prefecture is a Prefectures of Japan, prefecture of Japan located on the island of Kyushu and the Ryukyu Islands. Kagoshima Prefecture has a population of 1,527,019 (1 February 2025) and has a geographic area of 9,187 Square kilometre, km2 (3,547 Square m ...

on the Japanese mainland on September 17. Ida was at the time the strongest typhoon to hit

on record, with a minimum sea-level pressure of 916.1

hPa The pascal (symbol: Pa) is the unit of pressure in the International System of Units (SI). It is also used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength. The unit, named after Blaise Pascal, is an S ...

(27.05

inHg Inch of mercury (inHg, ″Hg, or in) is a non- SI unit of measurement for pressure. It is used for barometric pressure in weather reports, refrigeration and aviation in the United States. It is the pressure exerted by a column of mercury in h ...

) and a maximum wind gust of , which was recorded at a weather station in Makurazaki. This reading makes the storm responsible for the second-lowest atmospheric pressure ever recorded in mainland Japan, after the 1934 Muroto typhoon. After passing over Japan, Ida turned northeast and weakened, eventually becoming extratropical and dissipating near the western

Aleutian Islands The Aleutian Islands ( ; ; , "land of the Aleuts"; possibly from the Chukchi language, Chukchi ''aliat'', or "island")—also called the Aleut Islands, Aleutic Islands, or, before Alaska Purchase, 1867, the Catherine Archipelago—are a chain ...

on September 20.

Impact and aftermath

More than 2,000 people were killed in the Hiroshima Prefecture after heavy rains brought by a weakening Ida caused severe landslides. The storm occurred just days after the Empire of Japan surrendered to the Allies in the

Pacific War The Pacific War, sometimes called the Asia–Pacific War or the Pacific Theatre, was the Theater (warfare), theatre of World War II fought between the Empire of Japan and the Allies of World War II, Allies in East Asia, East and Southeast As ...

, formally ending

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, and the damage caused by Ida worsened the situation in the already war-ravaged country. In addition, the storm affected many ships of the United States Navy's Pacific Fleet. USS ''Repose'' (AH-16) reportedly entered Ida's eye and observed an atmospheric pressure of 25.55 inches of mercury (about 865 hPa). This is below the official world record for minimum sea-level pressure (870 hPa) recorded during Typhoon Tip in 1979, although ''Repose'' data is not confirmed.

References

{{DEFAULTSORT:Ida (1945) History of Kagoshima Prefecture History of Hiroshima Prefecture 1945 in Japan Typhoons in Japan 1940s Pacific typhoon seasons Tropical cyclones in 1945