Not all turbulence is the same. There are four distinct types, each with different causes, altitudes, predictability — and different routes where you're most likely to encounter them.
Clear-air turbulence is the most common type on long-haul flights and the least predictable. It occurs in cloudless skies at cruise altitude (28,000–42,000 ft) where fast-moving jet stream air meets slower air masses. The wind shear between these layers creates invisible eddies that aircraft fly through without warning — no clouds, no radar return, nothing visible from the cockpit window. CAT is most intense just below the jet stream core. Transatlantic and transpacific routes cross jet stream boundaries regularly, making CAT the defining turbulence experience on these flights. A 2023 study found North Atlantic severe CAT increased 55% from 1979–2020 due to climate change strengthening the jet stream.
Mountain wave turbulence forms when fast-moving wind flows over a mountain range, creating standing waves that extend far above and downwind of the peaks. Unlike CAT, this type is highly predictable — it occurs over the same locations whenever wind conditions are right. The Andes in South America produce the world's highest sustained turbulence (the Santiago–Mendoza route is the most turbulent commercial route on earth). The Rocky Mountains in North America affect flights over Denver, Salt Lake City, and Aspen, particularly in winter and spring. The Alps affect European routes between Italy, Switzerland, and Austria. Mountain wave turbulence can reach 50,000 ft on severe days.
Convective turbulence is associated with thunderstorms and cumulonimbus clouds. Strong vertical air movement (updrafts of 50–100 mph inside a thunderstorm) creates the most violent turbulence type. Pilots can see convective cells on weather radar and typically route around them, but the turbulence extends well beyond the visible cloud boundaries — up to 20 miles from a severe thunderstorm. Convective turbulence is most common in summer afternoons and in tropical regions. Southeast Asian routes in monsoon season (June–September) and US thunderstorm corridors (central and southern US in summer) are most affected.
Wake turbulence is created by the vortices trailing from an aircraft's wingtips. A heavy aircraft (777, A380) creates powerful wing-tip vortices that can roll a lighter following aircraft. On takeoff and landing, wake turbulence is a serious safety concern — which is why minimum spacing between aircraft is strictly regulated. At cruise altitude, wake turbulence dissipates quickly and is rarely a factor. The main exposure is during approach in busy airports when aircraft are closely spaced. Air traffic controllers maintain minimum separation standards specifically to prevent wake turbulence encounters.
Ranked by historical turbulence score — click any route for details