What was the biggest known tornado?
The Hallam, Nebraska F4 tornado of 22 May 2004 is the newest record-holder for peak width, at nearly two and a half miles, as surveyed by Brian Smith of NWS Omaha. This is probably close to the maximum size for tornadoes; but it is possible that larger, unrecorded ones have occurred. BACK UP TO THE TOP What single month had the most tornadoes? The record for most tornadoes in any month (since modern tornado record keeping began in 1950) was set in May 2003, with 543 tornadoes confirmed in the final numbers. This easily broke the old mark of 399, set in June 1992. For more on the most active tornado month, see the May 2003 Tornado Statistics page. BACK UP TO THE TOP What was the strongest tornado? What is the highest wind speed in a tornado? Nobody knows. Tornado wind speeds have only been directly recorded in the weaker ones, because strong and violent tornadoes destroy weather instruments. Mobile Doppler radars such as the OU Doppler on Wheels have remotely sensed tornado wind speeds
