The following statistics and definitions are derived from the Storm Prediction Center (SPC) historical tornado archive. The Tornado History Project can not guarantee the accuracy of the underlying data within the SPC historical tornado archive. However, the data as presented here is guaranteed to match the SPC data, except where noted.

Some definitions will not be given since they are obvious (i.e. "Date", "Time", etc...)
Special Note: This site uses a unique index number to identify each tornado. This index number is not a part of the official historical tornado archive.

E (Error) (tornado search table only) - A yellow box indicates that the tornado record contains a suspected error. A red box indicates that the tornado record contains an error and has been modified from the official source. Hover over the box for the error text.
Map/Forum (tornado search table only) - Clickable icons for further content related to a tornado.
State - The state or states affected by a tornado.
Fujita - The Fujita scale is an attempt to classify damage from a tornado. F0 being the least damaging, F5 the most. For 2007 and beyond, the Enhanced Fujita (EF) is given.
Fat. - The number of fatalities attributed to the tornado.
Inj. - The number of injuries attributed to the tornado.
Width - Width in yards. It is unclear if this indicates a maximum width or mean width.
Length - Length of tornado path in miles. Note the entire track length is not necessarily all on the ground (some tornadoes "hop and skip".)
Damage - Prior to 1996, this is a range by dollar amount. For 1996 and later, actual damage estimates are in millions.
Crop Loss - Added in 2007. Given in millions of dollars.
Lat/Lon - Contains two sets of coordinates:

• Touchdown Latitude/Longitude - For single state tornadoes, and the overall record for multi-state tornadoes, the approximate touchdown location in decimal degrees. For the state specific records of multi-state tornadoes, entry point into the state in decimal degrees.
  
• Liftoff Latitude/Longitude - For single state tornadoes, and the overall record for multi-state tornadoes, the approximate liftoff location in decimal degrees. For the state specific records of multi-state tornadoes, the exit or lift-off point from the state in decimal degrees.
  

St. #. - The state tornado number assigned to the tornado for that specific state for that specific year. Generally, state tornado numbers were assigned in the order the tornado occurred, but that is not always the case.
SPC # - The tornado number as assigned by the SPC. Tornado numbers are not unique and reset each year. Generally, tornado numbers were assigned in the order the tornado occurred, but that is not always the case.