Is Turbulence Getting Worse? What the Data Actually Shows

After Singapore Airlines flight SQ321 dropped roughly 54 metres in five seconds over Myanmar in May 2024 — killing one passenger and injuring 144 — the same question turned up everywhere: is turbulence actually getting worse, or are we just hearing about it more?

The honest answer is: yes, it's getting worse, and we now have peer-reviewed data to prove it. But the picture is more nuanced than the headlines suggest.

What a 2023 study from the University of Reading found

In June 2023, atmospheric scientists Mark Prosser, Paul Williams, Graeme Marlton, and Giles Harrison published Evidence for Large Increases in Clear‐Air Turbulence Over the Past Four Decades in Geophysical Research Letters. They reanalysed 40 years of atmospheric data (1979–2020) and measured how the duration of clear-air turbulence over a typical point on the busiest transatlantic corridor had changed.

The results, summarised by the University of Reading, are unambiguous:

Turbulence intensity	Annual hours (1979)	Annual hours (2020)	Change
Light	466.5	546.8	+17%
Moderate	70.0	96.1	+37%
Severe	17.7	27.4	+55%

Severe turbulence — the kind that injures passengers — increased the most, in proportional terms. Professor Williams put it plainly in the press release: "Following a decade of research showing that climate change will increase clear-air turbulence in the future, we now have evidence suggesting that the increase has already begun."

Why is it increasing? The jet stream is changing

Clear-air turbulence (CAT) is generated mainly by wind shear inside and around jet streams — the high-altitude rivers of fast-moving air at the boundary between warm tropical air and cold polar air. Two things determine how strong that shear gets:

1. The temperature gradient between the tropics and the poles
2. The vertical structure of that gradient (the troposphere vs the stratosphere)

A warming climate is heating the tropical upper troposphere faster than the lower stratosphere. That sharpens the vertical wind shear inside jet streams, and sharper shear means more eddies that pilots experience as bumps. Earlier modelling work from the same group projects that, on current warming pathways, severe CAT on busy North Atlantic and North Pacific routes could double or triple by the second half of this century.

The injury record: 2024 was the wake-up year

Statistically, severe turbulence injuries are still rare. The NTSB's 2021 safety study found 111 turbulence accidents on U.S. Part 121 air carriers from 2009 to 2018, with flight attendants making up 79% of seriously injured occupants. Cabin crew are roughly 24 times more likely than passengers to be seriously hurt — because they're the ones not strapped in.

But the trend line of high-profile incidents tells its own story:

• 21 May 2024 — Singapore Airlines SQ321 (Boeing 777, London to Singapore): 1 fatality, 144 injuries. Aircraft pulled +1.57G then –0.44G in a 19-second window after flying into a developing convective cell over Myanmar.
• August 2024 — A United flight from Cancún to Chicago diverted to Memphis with seven injured.
• March 2025 — A United flight from San Francisco to Singapore hit severe turbulence injuring five, including a flight attendant seriously.

And it's not just U.S. carriers. Korean Air stopped serving instant noodles in 2024 after burn injuries from turbulence, telling reporters that the number of turbulence incidents on its flights had doubled between 2009 and 2024.

So is your next flight more dangerous?

Not in the way most people fear. Modern airliners are certified to withstand loads roughly 1.5× the worst turbulence ever recorded, and structural failures from turbulence are essentially unheard of on commercial transport aircraft. The risk is almost entirely to unbelted occupants during the encounter itself.

The practical implications of the trend are:

• Buckle up whenever you're seated. This is the single biggest control you have. The fatality on SQ321 had a heart attack-adjacent medical event; nearly all serious injuries on the flight were to people not wearing seatbelts.
• Expect more "seatbelt sign on" time. Many airlines have already tightened seatbelt-sign procedures since 2024.
• The smoothness of any individual flight depends on weather, not the long-term trend. A specific Tuesday in May 2026 on JFK–LHR might be calmer than the same flight in 1995. Trends are statistical.

How forecasting is catching up

The good news: the same era that's producing more turbulence has also produced better tools for finding and avoiding it.

• The NCAR Graphical Turbulence Guidance (GTG) system now produces gridded CAT, mountain-wave, and low-level turbulence forecasts up to 12 hours ahead.
• The IATA Turbulence Aware platform, launched in 2018, pools anonymised Eddy Dissipation Rate (EDR) data from thousands of flights and feeds it back to dispatchers in near real time.
• Consumer products like Turbcast make those forecasts visible to passengers, not just dispatchers.

FAQ

Is climate change definitely the cause?

The trend matches what climate models predict, and the mechanism (sharper vertical wind shear from differential upper-tropospheric warming) is well understood. The Reading group is careful to say the evidence is "consistent with" climate change rather than claim it as the only cause — but it's the strongest hypothesis on the table.

Why does severe turbulence get the biggest percentage increase?

Severe CAT depends on tail-end extremes of the wind-shear distribution. When you shift the mean of a distribution, the tails move proportionally more — small percentage shifts in mean conditions create large percentage shifts in rare extremes. This is the same reason a small warming average produces big increases in heatwave frequency.

Are some routes affected more than others?

Yes. The North Atlantic and North Pacific corridors — where jet streams are strongest — show the biggest increases. Tropical routes are dominated by convective (thunderstorm) turbulence, which is changing differently. You can check turbulence forecasts route by route on Turbcast to see how your specific corridor compares.

Will pilots adapt their routes?

They already are. Long-haul flights frequently re-plan around forecast CAT, especially on the North Atlantic Organized Track System where routes are restructured daily. But re-routing burns extra fuel, and Williams' group estimates the additional fuel burn from turbulence avoidance is already costing airlines hundreds of millions of dollars annually.

The takeaway

Severe clear-air turbulence on busy long-haul routes has increased roughly 55% in 40 years, and the trend is consistent with what climate science predicts. Your individual flight is still overwhelmingly likely to be uneventful, but the rational response to the trend is the simplest one in aviation safety: wear your seatbelt whenever you are seated, and check the turbulence forecast for your route before you fly.