Typhoon Ida 1958

A record pressure over the Pacific

Ida developed near Guam on 20 September and moved west before turning north. Reconnaissance crews observed a rapidly deepening cyclone on 23–24 September. A dropsonde measured 877 hPa, the lowest tropical-cyclone pressure recorded at the time. The current archive places that minimum at 06:00 UTC on 24 September and peak one-minute winds of 175 kt six hours later.

Torrential rain in Japan

Ida weakened as it approached southeastern Honshu on 26 September. Rainfall reached 748.6 mm on Mount Amagi, while Tokyo received nearly 430 mm, its highest daily total since observations began in 1876. Rivers overflowed across the affected region, with especially severe flooding along the Kano River on the Izu Peninsula.

The rain triggered at least 1,900 landslides. Floodwater entered more than 520,000 homes, and the storm destroyed more than 244 road or railway bridges. Power failures and damaged transport links disrupted Tokyo, while broken communications cut off the hardest-hit communities on Izu.

Losses and relief work

The recorded death toll of 1,269 includes 381 people missing and presumed dead. Another 1,138 people suffered injuries, and about 12,000 lost their homes. Damage totaled an estimated US$50 million in 1958 dollars. U.S. military personnel and supplies joined the relief effort after the storm.