Turbulence intensity is measured using standardized scales that translate atmospheric motion into passenger experience. Here's how the EDR scale works, what each category means, and why the same turbulence feels different on different aircraft.
EDR (Eddy Dissipation Rate) is the international standard for measuring turbulence intensity in aviation. It measures the rate at which turbulent kinetic energy dissipates in the atmosphere, expressed in m²/³s⁻¹. EDR has replaced older qualitative scales because it's objective — measured automatically by sensors on commercial aircraft (accelerometers and GPS) rather than by a pilot's subjective perception. EDR values: 0–0.15 = smooth or light turbulence, 0.15–0.35 = light-to-moderate, 0.35–0.55 = moderate-to-severe, 0.55–0.8 = severe, 0.8+ = extreme. TurboTrack uses EDR data aggregated from thousands of commercial flights daily to build route turbulence scores.
The International Civil Aviation Organization (ICAO) defines four turbulence intensity categories used in official aviation weather reports (PIREPs, SIGMETs): (1) Light — slight erratic changes in altitude/attitude. Unsecured items may shift slightly. Passengers feel a slight strain against their seatbelts. (2) Moderate — changes in altitude/attitude occur but aircraft remains in positive control. Unsecured items become dislodged. Walking is difficult. (3) Severe — large, abrupt changes. Aircraft may be momentarily out of control. Impossible to walk, unsecured items fly around. (4) Extreme — aircraft is violently tossed about and practically impossible to control. May cause structural damage. Extremely rare on commercial flights.
Ranked by historical turbulence score — click any route for details