The question of whether to open a window during a tornado addresses a widespread misunderstanding about tornado physics. Meteorologists and safety experts are straightforward: do not open your windows. This action wastes precious time that should be spent securing yourself in a safe location.
Addressing the Pressure Equalization Myth
The idea of opening windows originated from a historical misconception about how tornadoes destroy buildings. It was once believed that the extremely low atmospheric pressure at the center of a tornado would create a significant pressure difference with the higher pressure inside a house. This differential was thought to cause the building to “explode” outward.
Proponents of this theory advised opening a window to allow the pressure to equalize quickly, preventing structural failure. Modern meteorological and engineering studies have rejected this theory, finding that the pressure difference is not the primary cause of destruction. Any pressure differential that occurs is often too minor and fleeting to be the sole factor in destroying a home.
If the pressure difference became large enough to cause failure, the windows themselves—the weakest points of the building envelope—would likely break naturally, equalizing the pressure within seconds. Spending time running through the house to open multiple windows is counterproductive. That time is better used moving to a designated shelter.
The True Danger: Wind and Debris
The actual forces responsible for the vast majority of tornado damage are the extreme wind loads and the impact from wind-borne debris, not the pressure drop. Tornadoes produce powerful winds that can exceed 200 miles per hour in intense storms, applying immense lift and shearing forces to a structure. These forces can rip a roof off or push walls inward regardless of the interior pressure.
Opening a window provides a path for high-velocity wind to enter the home, which can drastically increase internal pressure instantly. Once the wind is inside, it can press upward on the roof and outward on the walls, accelerating structural breakdown. This is contrary to the original myth, as wind entering the structure causes the most rapid failure.
Additionally, the wind turns everyday objects into deadly missiles, which is the leading cause of injury and death during a tornado. An open window creates a direct, unobstructed entry point for debris like wood, metal, or glass. The goal is to keep the building envelope intact, and a closed window, though fragile, is better than an open one.
Immediate Actions for Survival
Upon receiving a tornado warning, every second counts, and the focus must immediately shift to seeking the safest shelter. The safest location is the interior part of a basement, underground storm cellar, or a FEMA-approved safe room. These areas provide substantial protection from the weight of a collapsing structure and flying debris.
If a basement is not available, the next best option is a small, windowless interior room on the lowest floor. This could be a central hallway, a bathroom, or a closet, as these smaller spaces often have more structural support. The objective is to put as many walls as possible between yourself and the outside.
Once in the shelter area, the most important action is to protect the head and neck from falling or flying objects. This can be achieved by getting under something sturdy, like a heavy workbench or table. For added protection, cover yourself with a thick blanket, sleeping bag, or mattress to shield your body from debris. Safety experts recommend keeping a helmet nearby to protect against head trauma, which is a common cause of serious injury.