Q: Was the lowest barometric pressure in U.S. history recorded during a hurricane?
Yes. The lowest barometric pressure ever measured on the U.S. mainland was 26.35 inches, set on Sept. 2, 1935, in Long Key, Fla., during the Category 5 “Labor Day” hurricane that killed more than 400 people. This is the third-lowest barometric pressure ever recorded during an Atlantic hurricane, behind only Wilma in 2005 and Gilbert in 1988 (both readings were recorded offshore).
The world’s low-pressure record of 25.69 inches was set over the Pacific Ocean, during Typhoon Tip in Oct. 1979.
For comparison, standard sea-level barometric pressure is 29.92 inches, while the highest pressure reading of all-time was 32.01 inches, set in the Soviet Union in Dec. 1968.
This USA TODAY resource page has more about understanding air pressure.
(Answered by Doyle Rice, USA TODAY's weather editor, April 28, 2008)