Published: June 2005
Did You Know?
In Did You Know? the National Geographic magazine team shares extra information we gathered to expand your knowledge of our featured subjects.

Tornadoes can occur anywhere in the world, any time of day and any day of the year. Still, June 11, 2004, is one for the record books. On that single day 25 tornadoes struck the state of Iowa, which usually sees 31 for the entire month (National Climatic Data Cente statistics).

Among those tornadoes was the one documented by Tim Samaras in our article "Direct Hit." Amazingly, there were no deaths or injuries in Iowa as a result of those tornadoes. The United States experiences more tornadoes than any other country—about a thousand every year, according to the National Weather Service's Storm Prediction Center.

And no, you shouldn't open the windows when you see a tornado. It's a myth that that equalizes air pressure and reduces damage; it just lets in more damaging wind. Forget the windows and get to a safe place.

—Alice J. Dunn