Tornadoes and Thunderstorms

Facts & Statistics: Tornadoes

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 ¼  mile.
(2) Enhanced scale: wind speeds represent maximum 3-second gusts. Implemented on February 1, 2007.

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

 

INSURED LOSSES

Tornadoes accounted for 39.1 percent of insured catastrophe losses from 1995 to 2014, according to Verisk’s Property Claim Services (PCS). In 2014 insured losses from U.S. tornadoes/thunderstorms totaled $12.3 billion, up from $10.3 billion in 2013. 2014 losses were the fourth highest annual total on record, according to Munich Re. The number of tornadoes dropped to 888 in 2014 from 907 in 2013, according to the National Oceanic and Atmospheric Administration (NOAA). There were 47 direct fatalities from tornadoes in 2014, down from 55 in 2013, according to NOAA. June was the top month for tornadoes in 2014, with 287 tornadoes. The U.S. experiences more tornadoes than any other country, according to a 2013 report by Lloyd’s of London.

The costliest U.S. catastrophe involving tornadoes, based on insured losses, occurred in April 2011. It hit Tuscaloosa, Alabama, and other areas and cost $7.7  billion in insured damages in 2014 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 $7.2 billion in insured losses in 2014 dollars. (See chart below.) The National Weather Service posts updated information on tornadoes.

THE 2014 TORNADO SEASON

NOAA data show that there were 888 tornadoes in 2014, compared with 907 in 2013. On April 27, 30 tornadoes formed in seven states (Arkansas, Iowa, Nebraska, Kansas, Oklahoma, Mississippi and Louisiana). Nineteen fatalities were reported. Many homes and buildings were damaged or destroyed in Arkansas, Oklahoma and Kansas, according to the Federal Emergency Management Agency. On April 28, tornadoes in five states (Alabama, Georgia, Kentucky, Mississippi and Tennessee) resulted in 15 fatalities.

Munich Re includes tornadoes in the "Severe Thunderstorms" category shown below.

 

NATURAL DISASTER LOSSES IN THE UNITED STATES, FIRST HALF 2015

 

Source: © 2015 Munich Re, NatCatSERVICE. As of June 2015.

View Archived Graphs

 

 

NUMBER OF TORNADOES AND RELATED DEATHS PER MONTH, 2014 (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 TEN MOST COSTLY U.S. CATASTROPHES INVOLVING TORNADOES (1)

($ millions)

      Estimated insured loss (2)
Rank  Date Location Dollars when
occurred
In 2014
dollars (3)
1 Apr. 22-28, 2011 AL, AR, GA, IL, KY, LA, MO,
MS, OH, OK, TN, TX, VA
$7,300 $7,652
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 7,232
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 4,001
4 Oct. 4-6, 2010 AZ 2,700 2,889
5 Apr. 6-12, 2001 AR, CO, IA, IL, IN, KS, KY, MI, MN,
MO, NE, OH, OK, PA, TX, WI
2,200 2,844
6 Mar. 2-3, 2012 AL, GA, IN, KY, OH, TN 2,500 2,574
7 Apr. 28-29, 2012 IL, IN, KY, MO, TX 2,500 2,574
8 May 12-16, 2010 IL, MD, OK, PA, TX 2,000 2,140
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 2,133
10 Apr. 13-15, 2006 IA, IL, IN, WI 1,850 2,113

(1) Based on data through May 6, 2015.
(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 2014 by ISO using the GDP implicit price deflator.

Source: Property Claim Services (PCS), a Verisk Analytics business.

 

 

TOP TEN STATES, BY NUMBER OF TORNADOES, 2014 (1)

Rank (2) State Number of tornadoes
1 Mississippi 91
2 Nebraska 87
3 Alabama 65
4 Iowa 63
4 Texas 63
6 Missouri 56
7 Colorado 54
8 Kansas 48
9 South Dakota 37
10 Georgia 35
10 Illinois 35
10 North Carolina 35

(1) Includes tornadoes that cross state lines.
(2) States with the same number receive the same ranking.

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

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TORNADOES AND RELATED DEATHS BY STATE, 2014 (1)

State Tornadoes Fatalities Rank (2) State Tornadoes Fatalities Rank (2)
Alabama 65 2 3 Montana 8 0 31
Alaska 0 0 (3) Nebraska 87 2 2
Arizona 2 0 38 Nevada 6 0 33
Arkansas 24 17 16 New Hampshire 0 0 (3)
California 11 0 28 New Jersey 0 0 (3)
Colorado 54 0 7 New Mexico 17 0 22
Connecticut 1 0 41 New York 10 4 29
Delaware 1 0 42 North Carolina 35 1 10
D.C. 0 0 (3) North Dakota 18 0 21
Florida 29 0 14 Ohio 21 0 19
Georgia 35 0 10 Oklahoma 13 1 26
Hawaii 0 0 (3) Oregon 0 0 (3)
Idaho 3 0 37 Pennsylvania 10 0 29
Illinois 35 0 10 Rhode Island 0 0 (3)
Indiana 23 0 17 South Carolina 7 0 32
Iowa 63 2 4 South Dakota 37 0 9
Kansas 48 0 8 Tennessee 23 2 17
Kentucky 33 0 13 Texas 63 0 4
Louisiana 16 0 24 Utah 0 0 (3)
Maine 2 0 38 Vermont 0 0 (3)
Maryland 2 0 38 Virginia 12 0 27
Massachusetts 5 0 35 Washington 4 0 36
Michigan 17 0 22 West Virginia 6 0 33
Minnesota 28 0 15 Wisconsin 20 0 20
Mississippi 91 16 1 Wyoming 16 0 24
Missouri 56 0 6 United States 1,057 47  

(1) Ranked by total number of tornadoes.
(2) States with the same number receive the same ranking.
(3) State had no tornadoes in 2014.
(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.

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TORNADOES AND RELATED DEATHS IN THE UNITED STATES, 1995-2014 (1)

 

Year Tornadoes Deaths Year Tornadoes Deaths Year Tornadoes Deaths
1995 1,234 30 2002 941 55 2009 1,156 21
1996 1,173 25 2003 1,376 54 2010 1,282 45
1997 1,148 67 2004 1,819 36 2011 1,691 553
1998 1,424 130 2005 1,264 38 2012 938 70
1999 1,345 94 2006 1,103 67 2013 907 55
2000 1,071 40 2007 1,098 81 2014 888 47
2001 1,216 40 2008 1,692 126      

(1) Excludes Puerto Rico. Excludes tornadoes crossing state lines. Counts these tornadoes as one event.

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

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U.S. CONVECTIVE LOSS EVENTS, 1980-FIRST HALF 2015

(2014 $ billions)

Source: 2015 Munich Re, NatCatSERVICE; Property Claim Services (PCS), a Verisk Analytics business. As of June 2015.

View Archived Graphs

 

 

U.S. TORNADO COUNT, FIRST HALF 2015

© 2015 Munich Re, NatCatSERVICE; NOAA. As of June 2015.