Facts + Statistics: Tornadoes and thunderstorms

Tornadoes

A tornado is a violently rotating column of air that extends from a thunderstorm and comes into contact with the ground, according to the National Oceanic and Atmospheric Administration (NOAA). In an average year about 1,000 tornadoes are reported nationwide, according to NOAA. Tornado intensity is measured by the enhanced Fujita (EF) scale. The scale rates tornadoes on a scale of 0 through 5, based on the amount and type of wind damage. It incorporates 28 different damage indicators, based on damage to a wide variety of structures ranging from trees to shopping malls.

The U.S. experiences more tornadoes than any other country in the world, according to a 2013 report by Lloyd’s of London. (See Executive Summary, page 4 of Tornadoes a Rising Risk? for additional findings and statistics.)

The Fujita Scale For Tornadoes

    Original F scale (1) Enhanced F scale (2)
Category Damage Wind speed (mph) 3-second gust (mph)
F-0 Light 40-72  65-85
F-1 Moderate 73-112 86-110
F-2 Considerable 113-157 111-135
F-3 Severe 158-207 136-165
F-4 Devastating 208-260 166-200
F-5 Incredible 261-318 Over 200

(1) Original scale: wind speeds represent fastest estimated speeds over one quarter of a mile.
(2) Enhanced scale: wind speeds represent maximum 3-second gusts.

Source: U.S. Department of Commerce, National Oceanic and Atmospheric Administration.

Tornadoes accounted for 40 percent of inflation-adjusted insured catastrophe losses from 1997 to 2016, according to Property Claim Services (PCS®), a Verisk Analytics® business. In 2016 insured losses from U.S. tornadoes/thunderstorms totaled $14 billion, up from $9.6 billion in 2015. The number of tornadoes rose to 1,406 in 2017 from 971 in 2016, according to the National Oceanic and Atmospheric Administration (NOAA). The 2017 total was the highest since 2011, when there were 1,691 tornadoes, including two spring events that resulted in over $14 billion in losses when they occurred. There were 35 direct fatalities from tornadoes in 2017, up from 18 in 2016, according to NOAA. May was the top month for tornadoes in 2016, with 287 twisters. The United States experiences more tornadoes than any other country, according to a 2013 report by Lloyd’s of London.

Insured Losses

The United States experiences more tornadoes than any other country. Tornadoes accounted for 39.9 percent of insured catastrophe losses from 1997 to 2016, according to Verisk’s Property Claim Services (PCS). A March 2017 report by Willis Re found that the average annual loss from severe convective storms is $11.23 billion (in 2016 dollars) compared to $11.28 billion from hurricanes, based on PCS data. In 2016 insured losses from U.S. tornadoes/thunderstorms totaled $14 billion, up from $9.6 billion in 2015. The National Oceanic and Atmospheric Administration notes that tornadoes can happen any time of year. The costliest U.S. catastrophe involving tornadoes, based on insured losses, occurred in April 2011. It hit Tuscaloosa, Alabama, and other areas, and cost $7.9 billion in insured damages (in 2016 dollars). That event was the 10th costliest U.S. catastrophe, based on insured losses, according to PCS. The second costliest catastrophe involving tornadoes, based on insured losses, struck Joplin, Missouri, and other locations in May 2011. The catastrophe cost $7.4 billion in insured losses in 2016 dollars. (See chart below.) The National Weather Service posts updated information on tornadoes.

Natural Catastrophe Losses In The United States, 2016

(Based on perils)

Source: © 2017 Munich Re, NatCatSERVICE; Property Claim Services (PCS®)*, a Verisk Analytics® business. As of February 2017.

View Archived Graphs

Number Of Tornadoes And Related Deaths Per Month, 2017 (1)

(1) Excludes Puerto Rico. A tornado that crosses state lines is counted as a single event in this chart.

Source: U.S. Department of Commerce, Storm Prediction Center, National Weather Service.

View Archived Graphs

Top 10 Costliest U.S. Catastrophes Involving Tornadoes (1)

($ millions)

      Estimated insured loss (2)
Rank Date Location Dollars when
occurred
In 2016
dollars (3)
1 Apr. 22-28, 2011 AL, AR, GA, IL, KY, LA, MO,
MS, OH, OK, TN, TX, VA
$7,300 $7,875
2 May 20-27, 2011 AR, GA, IA, IL, IN, KS, KY, MI,
MN, MO, NC, NE, NY, OH, OK,
PA, TN, TX, VA, WI
6,900 7,443
3 May 2-11, 2003 AL, AR, CO, GA, IA, IL, IN, KS,
KY, MO, MS, NC, NE, OH, OK,
SC, SD, TN
3,205 4,118
4 Oct. 4-6, 2010 AZ 2,700 2,973
5 Apr. 6-12, 2001 AR, CO, IA, IL, IN, KS, KY, MI,
MN, MO, NE, OH, OK, PA,
TX, WI
2,200 2,927
6 Mar. 2-3, 2012 AL, GA, IN, KY, OH, TN 2,500 2,648
7 Apr. 28-29, 2012 IL, IN, KY, MO, TX 2,500 2,648
8 May 12-16, 2010 IL, MD, OK, PA, TX 2,000 2,202
9 Apr. 27-May 3, 2002 AR, GA, IL, IN, KS, KY, MD, MO,
MS, NC, NY, OH, PA, TN, TX,
VA, WV
1,675 2,195
10 Apr. 13-15, 2006 IA, IL, IN, WI 1,850 2,175

(1) Based on data through May 30, 2017.
(2) Property coverage only. In addition to losses due to tornadoes themselves, amounts may include losses due to hail, wind and flooding during the same event.
(3) Adjusted for inflation through 2016 by ISO using the GDP implicit price deflator.

Source: The Property Claim Services® (PCS®) unit of ISO®, a Verisk Analytics® company.

View Archived Tables

Top 10 States, By Number Of Tornadoes, 2017 (1)

Rank State Number of tornadoes Fatalities
1 Texas 176 4
2 Georgia 131 16
3 Missouri 102 1
4 Louisiana 88 3
5 Mississippi 81 5
6 Kansas 74 0
7 Alabama 65 0
8 Illinois 65 3
9 Oklahoma 62 1
10 Iowa 57 0

(1) Tornadoes that cross state lines are counted in every state in which they touch down.

Source: U.S. Department of Commerce, Storm Prediction Center, National Weather Service.

View Archived Tables

Tornadoes And Related Deaths By State, 2017 (1)

State Tornadoes Fatalities Rank (2) State Tornadoes Fatalities Rank (2)
Alabama 65 0 7 Montana 2 0 37
Alaska 0 0 (3) Nebraska 38 0 16
Arizona 3 0 34 Nevada 0 0 (3)
Arkansas 26 0 22 New Hampshire 0 0 (3)
California 2 0 37 New Jersey 2 0 37
Colorado 20 0 26 New Mexico 11 0 29
Connecticut 0 0 (3) New York 12 0 28
Delaware 1 0 41 North Carolina 34 0 19
D.C. 1 0 41 North Dakota 41 0 15
Florida 41 0 13 Ohio 43 0 12
Georgia 131 16 2 Oklahoma 62 1 9
Hawaii 0 0 (3) Oregon 3 0 34
Idaho 1 0 41 Pennsylvania 26 0 22
Illinois 65 3 7 Rhode Island 0 0 (3)
Indiana 36 0 17 South Carolina 51 1 11
Iowa 57 0 10 South Dakota 21 0 25
Kansas 74 0 6 Tennessee 35 0 18
Kentucky 29 0 20 Texas 176 4 1
Louisiana 88 3 4 Utah 0 0 (3)
Maine 10 0 31 Vermont 0 0 (3)
Maryland 4 0 33 Virginia 23 0 24
Massachusetts 2 0 37 Washington 3 0 34
Michigan 11 0 29 West Virginia 5 0 32
Minnesota 41 0 13 Wisconsin 28 1 21
Mississippi 81 5 5 Wyoming 15 0 27
Missouri 102 1 3 United States 1,522 35  

(1) Ranked by total number of tornadoes.
(2) States with the same number receive the same ranking.
(3) State had no tornadoes in 2017.
(4) The U.S. total will not match data used in other charts because it counts tornadoes that cross state lines.

Source: U.S. Department of Commerce, Storm Prediction Center, National Weather Service.

View Archived Tables

Tornadoes And Related Deaths In The United States, 1998-2017 (1)

Year Tornadoes Deaths Year Tornadoes Deaths
1998 1,424 130 2008 1,692 126
1999 1,345 94 2009 1,156 21
2000 1,071 40 2010 1,282 45
2001 1,216 40 2011 1,691 553
2002 941 55 2012 938 70
2003 1,376 54 2013 906 55
2004 1,819 36 2014 886 47
2005 1,264 38 2015 1,177 36
2006 1,103 67 2016 971 18
2007 1,098 81 2017 1,406 35

(1) Excludes Puerto Rico. A tornado that crosses state lines counts as one event.

Source: U.S. Department of Commerce, Storm Prediction Center, National Weather Service.

View Archived Tables

U.S. Convective Loss Events, 1980-2015

(2015 $ billions)

Source: © 2016 Munich Re, NatCatSERVICE; Property Claim Services (PCS®)*, a Verisk Analytics® business. As of January 2016.

View Archived Graphs

U.S. Tornado Count, 2017

 

Source: U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Weather Service.

View Archived Graphs

Back to top