In summary, the NASA programs have indicated that : 1) For the higher flight altitudes (40,000 to 75,000 ft) turbulence is both less frequent and less severe than for the lower altitudes (20,000 to 40,000 ft).

Generally, yes, there is less frequent and less severe turbulence at 40,000 feet compared to lower altitudes like 30,000 feet. At this height, aircraft are flying in the lower stratosphere, above most weather systems and "convective" turbulence (caused by storms and rising heat). Statistically, NASA data indicates that turbulence is encountered about 2% of the time at 40,000+ feet, compared to roughly 5% at lower altitudes. However, a major exception is Clear Air Turbulence (CAT) associated with the Jet Stream. In 2026, with the warming atmosphere, CAT is becoming more common and unpredictable. While 40,000 feet gets you "above the clouds," it puts you right in the path of high-altitude winds that can cause sudden, sharp jolts even in a clear blue sky. This is why pilots often "step climb" to higher altitudes as the plane gets lighter: not just for fuel efficiency, but to find "smoother air." Regardless of the altitude, the standard peer-to-peer advice remains: keep your seatbelt fastened whenever you are seated.