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.

2020 Tornadoes: In 2020 through mid-October there were 1,180 tornadoes compared with 1,429 in the first ten months of 2019, according to the National Oceanic and Atmospheric Administration (NOAA). In 2020 through mid-October, 78 people perished in tornadoes compared with 38 in the first ten months of 2019. On April 12 and 13, 32 people perished in tornadoes in Georgia, Mississippi, South Carolina and Tennessee. Those tornadoes were part of a larger convective storm system that spanned 23 states and the District of Columbia from April 10 to April 14 and caused $2.6 billion in insured losses, according to Property Claims Services (PCS), a Verisk Analytics company. On March 2 and 3, 25 people were killed in tornadoes in central Tennessee, including the city of Nashville. Tornado deaths in 2020 are the highest since 2011, when 553 people were killed in 1,691 tornadoes. PCS also reports that a convective storm system affected 11 states from August 8 to August 11 and caused $2.9 billion in insured losses.

2019 Tornadoes: NOAA reports that there were 1,520 tornadoes in 2019 compared to 1,126 in 2018. Tornadoes killed 41 people in 2019, compared with 10 people in 2018. In 2019 U.S tornadoes and thunderstorms caused $20.3 billion in insured losses according to Munich RE, up from $14.1 billion in 2018.

On March 3, 2019 a tornado struck southeast Alabama as part of a severe storm system that resulted in catastrophic damage in Alabama, Georgia, South Carolina and Florida. Twenty-three people were killed in the March 3 tornado in Lee County, Alabama. In Beauregard, Alabama, the tornado left a half-mile wide path of destruction. The National Weather Service said that the tornado was F4 strength with top winds of 170 miles per hour. The tornado storm system of March 3 was the deadliest outbreak in the United States since a system in Arkansas and Mississippi in April 2014 killed 35 people.

There were 272 tornadoes in April which caused seven deaths: two each in Texas, Louisiana and Oklahoma and one in Mississippi. There were 506 tornadoes recorded in May, the worst month for tornadoes in 2019. These tornadoes claimed another seven lives, including three in Missouri, two in Oklahoma and one each in Iowa and Ohio. Tornadoes from May 26 to May 29 in 13 states caused $3.4 billion in losses, according to the Property Claim Services unit of ISO. On October 20 and 21, a severe thunderstorm outbreak ripped through Texas, Oklahoma, Missouri, Arkansas, Tennessee and Louisiana, and produced several tornadoes including an EF-3 affecting the Dallas, Texas area. Aon said insured losses may reach the hundreds of million dollars. In December 72 tornadoes formed, causing two deaths in Alabama and one in Louisiana.

Insured Losses

Convective storms are the most common and damaging natural catastrophes in the United States, according to the Insurance Information Institute’s May 2020 white paper, Severe convective storms. According to catastrophe modeling company RMS, insured losses in the United States from these storms average about $17 billion on average each year, nearly equal to the losses incurred by hurricanes. While scientists cannot say that these storms are increasing, it is clear that the losses are increasing, as a result of population growth and economic development. In addition, the geography, frequency and intensity of these storms also may be changing. According to Aon, there were 14 separate billion-dollar economic, or total loss severe convective events in 2020. The most expensive included the August 10 Midwest derecho, or straight lines winds.

The United States experiences more tornadoes than any other country. 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 $8.4 billion in insured damages (in 2019 dollars). The second costliest catastrophe involving tornadoes, based on insured losses, struck Joplin, Missouri, and other locations in May 2011. The catastrophe cost $7.9 billion in insured losses in 2019 dollars. (See chart below.) The National Weather Service posts updated information on tornadoes.

Natural Catastrophe Losses In The United States, 2019

(Based on perils; US$ millions)

Source: © 2020 Munich Re, NatCatSERVICE; Property Claim Services (PCS®)*, a Verisk Analytics® business. As of June 2020.

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Number Of Tornadoes And Related Deaths Per Month, 2019 (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.

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

($ millions)

      Estimated insured loss (2)
Rank Date Location Dollars when occurred In 2019 dollars (3)
1 Apr 22-28, 2011 AL, AR, GA, IL, KY, LA, MO, MS, OH, OK, TN, TX, VA $7,300 $8,359
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 7,901
3 May 26-29, 2019 CO, IL, IN, IA, KS, MO, NE, NJ, NY, OH, OK, PA, WY 3,437 3,437
4 May 2-11, 2003 AL, AR, CO, GA, IA, IL, IN, KS, KY, MO, MS, NC, NE
OH, OK, SC, SD, TN
3,205 4,361
5 August 8-11, 2020 IA, IL, IN, KS, MI, MN, MO, NE, OH, SD, WI 2,900 2,900 (4)
6 Oct 4-6, 2010 AZ 2,700 3,156
7 April 10-14, 2020 AL, AR, CT, DC, DE, FL, GA, KS, LA, MA, MD, MS,
NC, NE, NJ. NY, OK, PA, RI, SC, TN, TX, VA, WV
2,600 2,600 (4)
8 May 8-11, 2017 CO, MO, NM, OK, TX 2,507 2,613
9 March 2-3, 2012 AL, GA, IN, KY, OH, TN 2,500 2,809
10 Apr 28-29, 2012 IL, IN, KY, MO, TX 2,500 2,809

(1) Based on data through September 30, 2020.
(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 2019 by the Insurance Information Institute using the GDP implicit price deflator.
(4) 2020 dollars.

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

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Top 10 States, By Number Of Tornadoes, 2019 (1)

 

Rank State Number of tornadoes Fatalities
1 Texas 188 2
2 Mississippi 138 2
3 Kansas 127 0
4 Oklahoma 99 4
5 Missouri 98 3
6 Louisiana 97 3
7 Alabama 95 25
8 Georgia 60 0
9 North Carolina 59 0
10 Ohio 59 1

(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.

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Tornadoes And Related Deaths By State, 2019 (1)

 

State Tornadoes Fatalities Rank (2) State Tornadoes Fatalities Rank (2)
Alabama 95 25 7 Montana 6 0 32
Alaska 0 0 (3) Nebraska 44 0 14
Arizona 10 0 30 Nevada 1 0 41
Arkansas 31 0 19 New Hampshire 0 0 (3)
California 16 0 27 New Jersey 9 0 31
Colorado 53 0 12 New Mexico 21 0 25
Connecticut 1 0 41 New York 4 0 36
Delaware 1 0 41 North Carolina 59 0 9
D.C. 0 0 (3) North Dakota 14 0 29
Florida 25 0 22 Ohio 59 1 9
Georgia 60 0 8 Oklahoma 99 0 4
Hawaii 0 0 (3) Oregon 4 4 36
Idaho 5 0 35 Pennsylvania 34 0 17
Illinois 37 0 16 Rhode Island 1 0 41
Indiana 39 0 15 South Carolina 18 0 26
Iowa 53 1 12 South Dakota 23 0 24
Kansas 127 0 3 Tennessee 16 0 27
Kentucky 28 0 21 Texas 188 2 1
Louisiana 97 3 6 Utah 0 0 (3)
Maine 1 0 41 Vermont 1 0 41
Maryland 6 0 32 Virginia 24 0 23
Massachusetts 3 0 38 Washington 2 0 40
Michigan 6 0 32 West Virginia 3 0 38
Minnesota 54 0 11 Wisconsin 32 0 18
Mississippi 138 2 2 Wyoming 30 0 20
Missouri 98 3 5 United States (4) 1,676 41  

(1) Ranked by total number of tornadoes.
(2) States with the same number of tornadoes receive the same ranking.
(3) State had no tornadoes in 2019.
(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, 2000-2019 (1)

Year Tornadoes Deaths Year Tornadoes Deaths
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 976 18
2007 1,098 81 2017 1,429 35
2008 1,692 126 2018 1,126 10
2009 1,156 21 2019 1,520 41

(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.

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U.S. Tornado Count, 2019

 

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

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Convective Storm Events* in the U.S., 1980-2018

(Overall and insured losses)

Source: © 2019 Munich Re, Geo Risks Research, NatCatSERVICE. As of March 2019. 

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Convective Storm Events* in the U.S., 1980-2018

(Overall losses: nominal, inflation adjusted, and normalized)

Source: © 2019 Munich Re, Geo Risks Research, NatCatSERVICE. As of March 2019. 

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