What Is Turbulence and Is It Dangerous?

The Short Answer: Turbulence Is Almost Never Dangerous

Turbulence is just rough air. It feels alarming, but commercial aircraft are engineered to handle far more than anything you'll experience as a passenger. No modern commercial aircraft has ever been brought down by turbulence alone. The real risk isn't to the plane. It's to unbuckled passengers who get tossed around the cabin.

Between 2009 and 2023, turbulence caused 185 serious injuries aboard U.S. commercial flights, according to the National Transportation Safety Board. That's roughly 12 serious injuries per year out of the nearly 900 million passengers who fly annually in the U.S. The odds are overwhelmingly in your favor.

That said, those injuries are real. And turbulence is getting worse due to climate change. So understanding what it is and how to protect yourself matters.

What Causes Turbulence

Turbulence is irregular air movement that causes sudden changes in the plane's altitude or attitude. Think of it like waves in the ocean, but in the atmosphere. The plane isn't falling. It's riding through uneven air currents.

Several things create these uneven currents:

• Temperature differences -- When the sun heats the ground unevenly, warm air rises in columns (thermals) while cooler air sinks, creating bumpy conditions.
• Jet streams -- Narrow bands of fast-moving air at high altitude. The edges of jet streams are prime turbulence zones.
• Mountains -- Wind flowing over mountain ranges creates waves and rotors on the downwind side, sometimes hundreds of miles from the peaks.
• Storms -- Thunderstorms produce intense updrafts and downdrafts. Pilots actively avoid these.
• Wake turbulence -- The vortices left behind by other aircraft, especially large ones.

The Types of Turbulence

Convective (Thermal) Turbulence

This is the most common type. The sun heats the ground, warm air rises, and the plane bounces through these thermals. You'll feel it most on afternoon flights over land, especially in summer. It's usually light to moderate and rarely a concern.

Clear Air Turbulence (CAT)

This is the one that catches everyone off guard. Clear air turbulence happens at high altitude, typically above 15,000 feet, with no visible clouds or storms to warn pilots. It's caused by wind shear near jet streams, where fast-moving air meets slower air.

CAT is the most dangerous type for passengers because it hits without warning. When you hear about injuries from turbulence, it's almost always CAT. The fasten seatbelt sign wasn't on because pilots didn't see it coming.

Mechanical Turbulence

Wind flowing over terrain features like mountains, buildings, or even the difference between a forest and an open field creates mechanical turbulence. It's most common at lower altitudes during takeoff and landing. Usually mild.

Mountain Wave Turbulence

When strong winds blow across mountain ranges, they create oscillating waves on the downwind side. These waves can extend well above the mountain peaks and far downwind. Flights near the Rockies, Andes, Alps, and Himalayas encounter this regularly. It can be severe.

Wake Turbulence

Every aircraft leaves spinning vortices of air behind its wingtips. The bigger the plane, the stronger the wake. This is why air traffic controllers space out departures and arrivals, and why small planes avoid following jumbo jets too closely. You might feel a brief jolt if your plane crosses the wake of another aircraft.

Frontal Turbulence

When two air masses of different temperatures collide (a weather front), the resulting turbulence can be significant. Warm fronts tend to produce slow, widespread bumpiness. Cold fronts can be sharp and intense but shorter in duration.

The Turbulence Scale: Light to Extreme

Pilots rate turbulence on a scale:

• Light -- Slight, erratic changes in altitude. Drinks barely ripple. This is what you feel on most flights at some point.
• Moderate -- Definite strain against seatbelts. Unsecured objects move around. Drinks slosh. Feels uncomfortable but isn't dangerous.
• Severe -- Large, abrupt changes in altitude. Walking is impossible. Unsecured passengers and objects are thrown around. This is rare. Most frequent flyers never experience it.
• Extreme -- The aircraft is violently tossed and practically impossible to control momentarily. Structural damage is possible. This is extraordinarily rare in commercial aviation.

The vast majority of what passengers experience is light turbulence. Moderate turbulence happens occasionally. Severe turbulence is rare. Extreme turbulence is something most pilots never encounter in an entire career.

Can Turbulence Crash a Plane?

No modern commercial aircraft has crashed due to turbulence. These planes are built to withstand forces far beyond what even extreme turbulence produces. During certification, aircraft wings are tested to bend up to 90 degrees before breaking. You'll never experience anything close to that in flight.

Pilots are also trained to manage turbulence. They adjust speed to the aircraft's designated "turbulence penetration speed," which provides the best combination of structural protection and controllability. They communicate with other pilots and air traffic control to find smoother altitudes.

Is Turbulence Getting Worse?

Yes. Research from the University of Reading found that severe clear air turbulence over the North Atlantic increased by 55% between 1979 and 2020. Moderate turbulence increased by 37% over the same period.

The cause is climate change. Rising carbon dioxide levels are increasing temperature differences in the upper atmosphere, which makes jet streams more volatile. More volatile jet streams mean more wind shear, which means more clear air turbulence at cruising altitude.

Scientists project that turbulence strong enough to cause injuries could double or triple in frequency by the end of the century. This doesn't mean flying will become dangerous, but it does mean wearing your seatbelt matters more than ever.

How to Stay Safe During Turbulence

• Keep your seatbelt fastened whenever you're seated. This is the single most important thing you can do. The vast majority of turbulence injuries happen to people who aren't buckled in. Keep it snug and low over your hips, even when the sign is off.
• Follow crew instructions immediately. When the captain turns on the seatbelt sign, get to your seat right away. Flight attendants aren't being cautious for fun.
• Secure loose items. Laptops, water bottles, and phones become projectiles in severe turbulence. Keep them stowed or held.
• Choose a seat over the wings. The center of the aircraft experiences the least movement during turbulence. Window seats in the front or back feel it more.
• Fly in the morning. Thermal turbulence is caused by the sun heating the ground. Morning flights, especially over land, tend to be smoother than afternoon flights.
• Check turbulence forecasts. Websites like Turbli.com let you check turbulence forecasts for your specific route before you fly.

What Pilots Do About Turbulence

Pilots aren't just riding it out. They're actively managing the situation:

• They receive turbulence reports from other aircraft on the same route (called PIREPs).
• They use onboard weather radar to identify and avoid storm cells.
• They communicate with air traffic control to request altitude changes if a smoother ride is available higher or lower.
• They slow the aircraft to turbulence penetration speed to reduce structural stress.
• They adjust routing to avoid known turbulence areas when possible.

The one thing they can't always see is clear air turbulence, because it's invisible to radar. That's why the seatbelt rule matters, and why CAT causes the most injuries.

The Bottom Line

Turbulence is one of the most common fears among air travelers, but the data is clear: it's overwhelmingly safe. The aircraft can handle it. The pilots are trained for it. The only variable is you. Wear your seatbelt, keep it snug, and keep it fastened even when the sign is off. Do that one thing and turbulence goes from a genuine concern to just an uncomfortable few minutes on an otherwise routine flight.