The Relationship Between Tornado Strength and Injury

Tornadoes are rated by the Fujita Scale, a tool developed by the late Professor Ted Fujita around 1970 to categorize tornado intensity based on the damages they cause to man-made structures.

WEAK TORNADOES,
F0-F1

  • 74% of all tornadoes
  • Less than 4% of tornado deaths
  • Lifetime 1-10+ minutes
  • Winds 40-110 mph
  • Light to moderate damage

STRONG TORNADOES,
F2-F3

  • 25% of all tornadoes
  • Nearly 29% of all tornado deaths
  • May last 20 minutes or longer
  • Winds 110-205 mph
  • Considerable to severe damage

VIOLENT TORNADOES,
F4-F5

  • Only 1% of all tornadoes
  • 67% of all tornado deaths
  • Lifetime can exceed one hour
  • Winds 205-318 mph
  • Devastating to incredible damage

1950-1994, Percent of
All Tornadoes

Pie chart shows 74% of all tornadoes are F0-F1, 25% are F2-F3, and 1% are F4-F5

  

1950-1994, Percent of
Tornado-Related Deaths

Pie chart shows 67% of deaths are caused by F4-F5 tornadoes, 29% by F2-F3, and 4% by F0-F1 tornadoes
 

Background image -- A careful analysis of a damage path in the Oklahoma City area following the 1999 Oklahoma/Kansas tornado outbreak shows that only 1.5% of the damage was at the F5 level (shown in red). Although the tornado itself was a mile wide at times and traveled 38 miles, the most intense damage was only a few blocks wide. The vast majority of homes sustained damage rated F3 or less.

Storm track analysis by Greg Stumpf

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