The National Weather Service (NWS) defines tornadoes as “a violently rotating column of air touching the ground, usually attached to the base of a thunderstorm.” Any thunderstorm can develop a tornado, but the most severe twisters are created inside supercell thunderstorms, defined by a rotating updraft. This rotation pulls in warmer air causing its rotation speed to increase. This is met by the cooler air, which creates energy within the storm.

Tornadoes are measured using the Enhanced Fujita Scale, which rates them from EF-0 to EF-5. Scales are determined by the NWS after a tornado based on the amount of damage viewed on the ground. This helps investigators estimate the highest approximate wind speed that was sustained for at least a three-second gust. An EF-0 tornado includes winds of 65-85 miles per hour, whereas an EF-5 includes winds of more than 200 miles per hour. An EF-1 may topple trees and billboards, while an EF-5 will move a strong-frame home from its foundation and carry it some distance.

While tornadoes are most common in North America, they can occur anywhere a thunderstorm forms and have been recorded in countries around the world and across every continent except Antarctica. Between 2002 and 2021, there were between 900 to almost 1,700 tornadoes a year in the United States. Known as “nature’s most violent storms,” the U.S. is home to more tornadoes than any other country in the world. Canada is home to the second-highest number of tornadoes every year. Because of its size, England is listed in the Guinness Book of Records as having the most tornadoes per land mass (1 per every 1,754 miles annually). The United Kingdom is third for the number of tornadoes. New Zealand and Japan, despite their small size, are fourth and fifth, and Australia is sixth.

Within the U.S., an area that stretches across northern Texas, Oklahoma, Kansas, Missouri, and portions of Colorado, Nebraska, Iowa and Louisiana has been colloquially known as Tornado Alley. Forecasters and emergency management officials are pushing for the end of the use of that term as tornadoes are happening outside of that region with increasing frequency. Europe’s ‘tornado alley’ is an area covering the European plains, stretching from northeast France, through Germany and into Poland, and features strong tornadoes in the summer.

Since 2000, tornadoes have killed an average of 75 Americans every year – however, this number is very high due to an extraordinarily high number of deaths in 2011, mostly due to an outbreak of tornadoes in late April. Removing the anomaly of 2011, the average number of Americans killed by tornadoes drops to just over 52. In the same period of time, tornadoes have caused an average of $1.4 billion in damage ($1.06 billion when 2011 is excluded). Most tornado deaths are caused by flying debris, which is why people are advised to go to a basement or an interior room in the home if one is approaching. People who live in mobile homes are advised to seek shelter underground or in a permanent building. Officials regularly remind people not to seek shelter in mobile homes as more than half of tornado-related deaths occur in this type of housing.

A 2022 paper in the Journal of Economic Studies found that both “poverty and African American status are linked to greater tornado damages.” The authors found that areas struck by tornadoes were more likely to have a higher percentage of Black residents, a lower percentage of people with at least a bachelor’s degree, and a lower median income. People living in poverty and Black people are less likely to be homeowners due to structural and historical discrimination and are left to the whims of rental building owners to determine whether their home will be rebuilt. This leads to a higher level of displacement and fewer affordable housing options available after a tornado, often changing the historical makeup and nature of the community at the same time.

The same paper also found that wealthier people will abandon tornado-damaged areas, leaving an increased number of people experiencing poverty in an area struggling to recover with less income from wealthy property owners. Additionally, the authors also found that Black residents are more likely to be displaced because they simply do not have access to the same economic and financial resources to rebuild.

Key Facts

  • Tornadoes tend to follow a fairly set pattern, though aberrations do occur. They typically move from the southwest to the northeast, though they have been reported in all directions. While tornadoes can occur at any time, most tornadoes occur between 4 p.m. and 9 p.m. The larger patterns associated with tornadoes are changing as scientists begin to see tornadoes appear more frequently in clusters instead of single tornadoes, the geographic area where tornadoes occur appears to be shifting eastward, and powerful tornadoes are happening more frequently in winter months. All these shifts are changing the risks associated with tornadoes and how people understand their tornado-related risks.
  • For those who live in the most tornado-prone areas, an understanding of the way tornadoes “usually” occur may lead to complacency. In addition, many myths about tornado safety lead to confusion. For example, it is a common myth that a vehicle can outrun a tornado or drivers that should hide under an overpass. The fact is that people should look for a nearby building or get out of their cars and into a low-lying ditch. Valuable time often is wasted when those in the path of the storm should be seeking shelter instead.
  • Since 1880, the percentage of fatalities during daytime tornadoes has decreased by 20% while the percentage of fatalities during nighttime tornadoes has increased by the same amountBetween 1880-1890, approximately 30% of tornado fatalities occurred at night. By 2010-2020 (the last period included in the study), the split was much closer to 50/50. Nighttime tornadoes kill twice as many people as daytime tornadoes annually. A study released in 2022 also found that tornadoes occurring at night affect more people, a finding the authors attributed to people being more widely distributed across geographic areas at night as opposed to when they may be clustered in areas with schools, as well as factories, offices and other workplaces.
  • The regions of the United States where tornadoes occur more frequently are shifting east. A 2021 study of the change in the number of days favorable to tornado formation found that areas around the Mississippi River and to the east of the Appalachian Mountains saw the largest increases. At the same time, tornado activity in areas like Oklahoma and Kansas decreased to some of the lowest numbers ever seen.
  • There is an acute need for weather information and warnings that are accessible to people with disabilities and functional needs. A 2020 study about tornado warnings among people with blindness or low vision found that the majority of those interviewed preferred television, phone alerts and radio for receiving weather warnings. The authors also said, “Comments from our interviews suggested that participants may prefer for common sources to be made accessible rather than use products designed specifically for people who are blind.” Participants also identified the need for information to be hyper-local, including the use of street names and other identifying landmarks to help distinguish where the areas of concern are.

How to Help

Donors hoping to mitigate the effects of future tornadoes and provide long-term recovery solutions could:

  • Support improving the accuracy of prediction and warning systems. Improved weather tracking and emergency alerting systems are needed to help give people enough information and enough time to seek shelter. As tornado-prone areas shift east, the nature of tornadoes is changing as well. In a blog about improving tornado warning time, Gene Grekner – the director of the Georgia Tech Severe Storms Research Center – said: “Here, tornadoes can come and go in 10 minutes, as opposed to an hour in Kansas.” Overall, education about tornado formation is needed as they move.
  • Advocate for better-built structures and codes to withstand high winds. In the areas that are historically most vulnerable to tornadoes, there are no building codes requiring structures to be built to withstand high winds, as there are in hurricane-prone areas. This is equally true when it comes to rental properties and apartment buildings, where residents likely don’t have insurance or financial support to rebuild destroyed structures and building owners are not obligated to rebuild damaged or destroyed apartments. While many structures are colloquially referred to as “mobile homes”, there have been no mobile homes built since 1976. Since June 15, 1976, every home that is built off-site and transported to its final location has been called a “manufactured home” and is subject to standards set in 1974. Mobile homes built before 1976 had no standards at all. Manufactured homes do not have the same structural integrity as permanent buildings because they are held in place by gravity instead of being directly attached to a pad or basement. As a result, they are more prone to having strong winds from tornadoes get under the manufactured house and topple it.
  • Support local nonprofit media organizations. Emergency alerts often cover multiple counties and dozens of communities – largely because the meteorologists who are issuing them from the NWS are often not at the epicenter of the storm. Local media organizations that can provide badly needed geographic information about where a tornado is can help people make better decisions about their safety and what actions they need to take.
  • Know where you live and where to find timely and accurate information. The NWS issues Tornado Warnings that are polygon-based and may include an entire county or portions of several counties. A 2022 study found that while NWS warnings were helpful, every person interviewed for the study (with one exception) “was an active manager of their risk.” They also sought out more information through weather apps and local news organizations that could provide more detailed information than broad weather warnings.
  • Improve the accessibility of tools that allow people to manage their own risk. Weather apps that provide near-real-time radar images, along with those that provide online streaming of emergency radio communications and other technological advancements have helped people manage their own risk when dealing with tornadoes. However, most of the apps are not fully accessible to people with disabilities and functional needs. Finding ways to increase access to the information that these technologies make available would increase the agency and autonomy of people with disabilities and functional needs to make their own decisions during emergencies.

What Funders Are Doing

  • Center for Disaster Philanthropy’s Midwest Early Recovery Fund (ERF) focuses on low-attention disasters that do not receive a FEMA federal disaster declaration. A few examples of tornado-related grants from ERF include:
    • $19,800 to the Castlewood Community Foundation to support casework, recovery task force development and children’s psychosocial needs in response to a tornado in May 2022.
    • $120,000 to the Northwest Arkansas Child Care Resource & Referral Center (now Child Care Aware of Northwest Arkansas) to support recovery needs for children and caregivers after the 2022 Springdale, Arkansas tornado. Funds will support the hiring of a specialist/coach for caregivers, training for over 500 providers, educators, parents and caregivers and a one-day conference providing education and information about trauma responses.
    • $103,400 to The Community House Foundation to support a disaster recovery coordinator for eighteen months of recovery coordination needs after the December 2021 tornado outbreak.
    • $110,000 to the Salvation Army Arkansas/Oklahoma Division for disaster case management services as they support recovery from the December 2021 northeast Arkansas tornadoes.
  • Other tornado-related grants from our Disaster Response Fund include:
    • $250,000 to the Bernard Project in 2022 to support the SBP FEMA appeals program which secures additional government resources for recovery to benefit those most in need of those resources.
    • $80,000 to the Northwest TN Development District to support two new employees focusing on disaster recovery for counties affected by tornadoes in December 2021.
    • $150,000 to the Felix E. Martin Jr. Foundation to build the capacity of the Muhlenberg County, Kentucky Long Term Recovery Group in 2022. This grant funds a disaster response coordinator to oversee the recovery process and provides for a disaster relief center. Additionally, funds will help address the unmet needs of residents affected by the 2021 tornado outbreak.

Additionally, CDP, in partnership with Google, made a $100,000 grant to People In Need in 2021 to support the response and recovery from a tornado in the Czech Republic.

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