With tornado season approaching, many homeowners wonder if they should open or close windows when a tornado hits. This debate has raged for decades among meteorologists and safety experts. Below we’ll examine the pros and cons of each approach, look at expert opinions, and provide best practices for keeping your home and family safe during a tornado.
The Case for Opening Windows
The main argument for opening windows is to equalize pressure inside and outside the house. Violent winds cause exterior pressure to fluctuate dramatically. If the inside pressure can’t equalize through open windows and doors, this extreme negative pressure can lead to the roof being ripped off and exterior walls collapsing.
According to retired National Oceanic and Atmospheric Administration (NOAA) meteorologist Chris Vaccaro, “Opening windows allows the inside pressure to equalize with the outside pressure, which eliminates the chances of your house exploding due to a pressure difference.”
In a 2002 study, Texas Tech wind engineers found that opening one window on the side of the house facing away from the tornado’s approach could reduce damage from exploding windows, roof damage, and collapsed walls.
Those in favor of the open window approach also point out that it is extremely difficult to close windows during the violently high winds of a tornado. You could be hit by flying debris while trying to close them. It’s safer to open them in advance.
Potential Downsides to Opening Windows
While equalizing pressure is beneficial, completely opening all windows on all levels of the house may introduce other risks:
- Flying debris, broken glass, and objects like lumber could easily enter the house through open windows, injuring occupants.
- Rain and water infiltration could cause substantial damage.
- It may be impossible to close any open windows if winds escalate to higher speeds, removing the option to shelter in place.
- Partial wall or roof failures may actually increase with all windows open, as wind tunnels through the house.
The Case for Closing Windows
The main argument for closing windows is to prevent wind, rain, flying debris from entering the house. Meteorologist Rochelle Zisholtz advises, “Close all windows tightly to prevent damaging winds from entering your house or shelter.”
Bill Bunting, Chief of Forecast Operations at the Storm Prediction Center agrees: “Make sure all of your windows are closed tightly. This will reduce the amount of debris and strong winds entering your house or shelter.”
According to FEMA, closing exterior doors and windows is the most important step when sheltering in place in a tornado. The goal is to create as many barriers between yourself and the extreme wind as possible.
Potential Downsides to Closing Windows
While closing windows has merits, there are also risks to be aware of:
- Rapid pressure changes during a tornado can still lead to window blowouts or roof/wall failures.
- It is dangerous to attempt to close windows during high winds and debris.
- Being unable to open windows fully could potentially trap dangerous fumes inside.
Expert Opinions on Open vs Closed Windows
There is no scientific consensus among experts on whether windows should be open or closed. Opinions diverge based on priorities and trade-offs.
In favor of keeping windows closed:
- The Centers for Disease Control (CDC) recommends keeping windows and doors closed and taking shelter in an interior room for maximum protection.
- The National Weather Service advises to “Get inside. Stay inside. Close windows and doors.”
- University of Florida engineering professor Forrest Masters states, “Closing the windows is definitely the best thing to do.”
In favor of opening windows:
- Popular Science recommends opening one window a crack on the side of the house opposite the tornado’s direction.
- Texas Tech wind engineers advise opening one window one inch on the side of the house facing away from the tornado.
- Retired NOAA meteorologist Chris Vaccaro says, “Opening windows allows the inside pressure to equalize with the outside pressure, which eliminates the chances of your house exploding due to a pressure difference.”
Many experts favor a balanced approach based on location and tornado severity:
- Michigan State University Extension recommends keeping windows closed in basements and first floors, but opening upper story and attic windows 1-2 inches.
- Iowa State University Extension advises to open windows only in rooms you are taking direct shelter in, keep others closed.
- The American Red Cross recommends opening a window or door on the leeward side of the house (opposite the wind direction) to relieve pressure during a weak tornado.
Best Practices for Window Safety During Tornadoes
Based on all available research, here are smart practices for window safety when a tornado is imminent:
- Prepare in advance: Make sure all household members know where to take shelter during a tornado warning. Identify the most secure interior room or basement, stock with blankets, flashlight and other supplies.
- Close exterior doors: Close and lock all outside doors once a tornado warning is issued. Exterior doors are vulnerable to high winds.
- Close windows on lower floors: Close and secure all windows and window coverings on lower floors and basement. Keeping first floor windows closed provides critical protection from wind, rain and debris.
- Open select upper floor windows: If safely possible, open one window no more than 1-2 inches on an upper floor on the side of the house opposite the approaching tornado.
- Stay away from all windows and exterior walls: Once in your shelter, get as far from windows and exterior walls as possible. Lay on the floor under a sturdy table or mattress for protection.
- Only open windows if tornado is weak: Only open upper windows if there is enough warning time before a weaker tornado strikes. Never open windows once high winds commence.
- Do not try to close windows once winds increase: It is extremely dangerous to approach windows when debris and high winds occur. Avoid at all costs.
- Have window covers ready: Have plywood or storm shutters to cover windows ready before storm season. Only attempt to install if ample warning time.
| Window Location | Open or Closed? |
|---|---|
| Basement windows | Closed |
| First floor windows | Closed |
| Upper floor windows | Open 1-2 inches on side opposite approaching tornado if time allows |
| Attic windows | Open 1-2 inches on side opposite approaching tornado if time allows |
Conclusion
Deciding whether to open or close windows during a tornado is a complex issue with merits on both sides. In general, close and secure all doors and windows on lower levels for maximum protection from wind and debris. If safely possible, slightly opening select upper floor windows may relieve internal pressure. Take shelter in a secure interior room away from windows. Do not attempt to adjust windows once high winds commence. Follow these best practices and expert guidance to give your home and loved ones the best chance of staying safe during a tornado.