Tornado facts and safety

What is a tornado?

A tornado, also known as a twister, is a violently rotating column of air that extends from a thunderstorm and make ground contact. Tornado intensity is measured by the Enhanced Fujita (EF) scale, which rates tornadoes from 0 through 5 based on the amount and type of wind damage.

How common are tornadoes?

An average of about 1,200 tornadoes is reported nationwide each year. Twisters are most common in the central United States, often referred to as “Tornado Alley,” but significant tornado activity also occurs in the Southeast, sometimes called “Dixie Alley.” Tornadoes can occur almost anywhere in North America, including in large cities.

Tornadoes can happen at any time of year and at any time of day or night, though they occur most frequently between early spring and July and during the late afternoon and early evening hours.

What are the warning signs of a tornado?

Signs that a twister may be approaching include:

• Dark greenish skies
• Large hail
• Dark, rotating, low-lying clouds (often called a wall cloud)
• A loud roar, like the sound of a freight train

Although meteorologists are now better able to detect tornado-producing storms, tornadoes can still strike with little warning. Therefore, it is best to be prepared well before severe weather approaches.

Many communities use outdoor warning sirens, and mobile phones can receive Wireless Emergency Alerts (WEA) and weather notifications when tornado warnings are issued.

What's the difference between a tornado watch and a tornado warning?

Both tornado watches and tornado warnings are issued by the National Oceanic and Atmospheric Administration (NOAA) and the National Weather Service (NWS). However, there are important differences between the two alerts.

Tornado watch

A tornado watch means that weather conditions are favorable for tornadoes to develop.

If a watch is issued:

• Stay alert to changes in the weather.
• Make sure all family members are accounted for.
• Monitor local radio, television, or weather apps for updates.
• Move vehicles into a garage if possible.
• Bring lawn furniture and outdoor equipment inside to reduce flying debris.

Tornado warning

A tornado warning means a tornado has been sighted or detected on weather radar in your area.

Danger is imminent and you may only have seconds to take cover immediately.

What to do when a tornado has been sighted

When a tornado warning is issued or a tornado has been sighted, do not try to outrun it. Stay calm but act quickly and seek shelter in the safest place possible.

If you are at home

The safest place to be is underground. Basements usually provide the most protection. If a basement is not available, take cover in an interior room away from windows, such as:

• A bathroom
• A closet
• An interior hallway
• Under a sturdy piece of furniture

If you are in an office building or skyscraper

Go directly to an enclosed, windowless area near the center of the building, away from glass and on the lowest floor possible. Crouch down and cover your head.

Interior stairwells often provide good shelter and allow access to lower floors quickly. Avoid elevators because power outages may trap occupants.

If you are at school

Follow staff instructions and move to an interior hallway or designated shelter area in an orderly manner. Crouch low, keep your head down, and protect the back of your head with your arms. Stay away from windows and large open rooms such as gyms and auditoriums.

If you are in a car or truck

If possible, drive to the nearest sturdy building or storm shelter. If shelter cannot be reached safely, abandon the vehicle and seek lower ground such as a ditch. Lie flat, face down, and protect the back of your head with your arms.

Safety precautions to take after a tornado

Tornadoes can leave behind dangerous conditions. Take caution when inspecting damage.

• Stay in your shelter until the storm has passed or emergency personnel say it is safe to leave.
• Check people around you for injuries and administer first aid if necessary.
• Avoid entering severely damaged buildings until authorities say they are safe.
• Check utility lines and appliances for damage. If you smell gas, open windows and turn off the main gas valve. Do not turn on lights or appliances until the gas has dissipated.
• If electrical wires are sparking or damaged, turn off the power if it is safe to do so.
• Outside, watch for downed power lines and stay away from standing water that may contain live electrical current.
• Be alert for leaking gas pipes or fuel tanks. Avoid using matches or lighters until hazards are cleared.
• Use flashlights instead of candles to reduce fire risk.

Recovering from a tornado

Damage caused by tornadoes is typically covered under standard homeowners and commercial property insurance policies. Damage to vehicles is covered under the optional comprehensive portion of an auto insurance policy.

If you sustain tornado damage:

• Contact your insurer as soon as possible to begin the claims process. After disasters, insurers typically prioritize the most severe losses first.
• Take photos or videos of all damage before making repairs. A photographic record can help support your insurance claim.
• Make temporary repairs to prevent further damage from rain, wind or theft. These costs are usually reimbursable, so keep receipts.
• Create a detailed list of damaged or destroyed personal property. A home inventory can make this process much easier.
• Do not discard damaged items until you have met with an insurance adjuster unless they pose a safety risk.
• Be cautious when hiring contractors. Work with reputable professionals, check references, and confirm payment terms before signing repair agreements.
• If your home is uninhabitable, your homeowners or renters insurance may cover Additional Living Expenses (ALE) such as hotel stays or meals while repairs are underway. Save all related receipts and keep your insurer informed about how to contact you.

If you have questions about your coverage, contact your insurance professional.

Additional Resources

• National Weather Service alerts
• NOAA/National Weather Service Storm Prediction Center

Next steps: Another atmospheric hazard that can strike quickly is lightning, stay safe by learning the difference between lightning myth and fact.